Compare sorting algorithms' performance
You are encouraged to solve this task according to the task description, using any language you may know.
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
Heap sort | Merge sort | Patience sort | Quick sort
O(n log2n) sorts
Shell Sort
O(n2) sorts
Bubble sort |
Cocktail sort |
Cocktail sort with shifting bounds |
Comb sort |
Cycle sort |
Gnome sort |
Insertion sort |
Selection sort |
Strand sort
other sorts
Bead sort |
Bogo sort |
Common sorted list |
Composite structures sort |
Custom comparator sort |
Counting sort |
Disjoint sublist sort |
External sort |
Jort sort |
Lexicographical sort |
Natural sorting |
Order by pair comparisons |
Order disjoint list items |
Order two numerical lists |
Object identifier (OID) sort |
Pancake sort |
Quickselect |
Permutation sort |
Radix sort |
Ranking methods |
Remove duplicate elements |
Sleep sort |
Stooge sort |
[Sort letters of a string] |
Three variable sort |
Topological sort |
Tree sort
Measure a relative performance of sorting algorithms implementations.
Plot execution time vs. input sequence length dependencies for various implementation of sorting algorithm and different input sequence types (example figures).
Consider three type of input sequences:
- ones: sequence of all 1's. Example: {1, 1, 1, 1, 1}
- range: ascending sequence, i.e. already sorted. Example: {1, 2, 3, 10, 15}
- shuffled range: sequence with elements randomly distributed. Example: {5, 3, 9, 6, 8}
Consider at least two different sorting functions (different algorithms or/and different implementation of the same algorithm).
For example, consider Bubble Sort, Insertion sort, Quicksort or/and implementations of Quicksort with different pivot selection mechanisms. Where possible, use existing implementations.
Preliminary subtask:
General steps:
- Define sorting routines to be considered.
- Define appropriate sequence generators and write timings.
- Plot timings.
- What conclusions about relative performance of the sorting routines could be made based on the plots?
AutoHotkey
; BUGGY - FIX
#Persistent
#SingleInstance OFF
SetBatchLines, -1
SortMethods := "Bogo,Bubble,Cocktail,Counting,Gnome,Insertion,Merge,Permutation,Quick,Selection,Shell,BuiltIn"
Gui, Add, Edit, vInput, numbers,separated,by,commas,without,spaces,afterwards
Loop, PARSE, SortMethods, `,
Gui, Add, CheckBox, v%A_LoopField%, %A_LoopField% Sort
Gui, Add, Button, gTest, Test!
Gui, Show,, SortTest!
Return
Test:
SplashTextOn,,, Test Commencing
Sleep 2500
SplashTextOff
Gui, +OwnDialogs
Gui, Submit, NoHide
Loop, PARSE, SortMethods, `,
{
If (%A_LoopField%)
{
DllCall("QueryPerformanceCounter", "Int64 *", %A_LoopField%Begin)
%A_LoopField%Out := %A_LoopField%Sort(Input)
DllCall("QueryPerformanceCounter", "Int64 *", %A_LoopField%Time)
%A_LoopField%End := %A_LoopField%Begin + %A_LoopField%Time
%A_LoopField%Time -= %A_LoopField%Begin
}
}
Time := ""
Loop, PARSE, SortMethods, `,
If (%A_LoopField%)
Time .= A_LoopField . " Sort: " . %A_LoopField%Time . "`t`t" . %A_LoopField%Out . "`r`n"
MsgBox,, Results!, %Time%
Return
; Sorting funtions (Bogo, Bubble, Cocktail, Counting, Gnome, Insertion, Merge, Permutation, Quick, Selection, Shell, BuiltIn):
BogoSort(var)
{
sorted := 1
Loop, Parse, var
{
current := A_LoopField
rest := SubStr(var, A_Index)
Loop, Parse, rest
{
If (current > A_LoopField)
sorted := 0
}
}
While !sorted {
sorted := 1
Loop, Parse, var, `,
{
current := A_LoopField
rest := SubStr(var, A_Index)
Loop, Parse, rest, `,
{
If (current > A_LoopField)
sorted := 0
}
}
Sort, var, D`, Random
}
Return var
}
BubbleSort(var)
{
StringSplit, array, var, `,
hasChanged = 1
size := array0
While hasChanged
{
hasChanged = 0
Loop, % (size - 1)
{
i := array%A_Index%
aj := A_Index + 1
j := array%aj%
If (j < i)
{
temp := array%A_Index%
array%A_Index% := array%aj%
array%aj% := temp
hasChanged = 1
}
}
}
Loop, % size
sorted .= "," . array%A_Index%
Return substr(sorted,2)
}
CocktailSort(var)
{
StringSplit array, var, `,
i0 := 1, i1 := array0
Loop
{
Changed =
Loop % i1-- -i0 {
j := i0+A_Index, i := j-1
If (array%j% < array%i%)
t := array%i%, array%i% := array%j%, array%j% := t
,Changed = 1
}
IfEqual Changed,, Break
Loop % i1-i0++
{
i := i1-A_Index, j := i+1
If (array%j% < array%i%)
t := array%i%, array%i% := array%j%, array%j% := t
,Changed = 1
}
IfEqual Changed,, Break
}
Loop % array0
sorted .= "," . array%A_Index%
Return SubStr(sorted,2)
}
CountingSort(var)
{
max := min := substr(var, 1, instr(var, ","))
Loop, parse, var, `,
{
If (A_LoopField > max)
max := A_LoopField
Else If (A_LoopField < min)
min := A_LoopField
}
Loop % max-min+1
i := A_Index-1, a%i% := 0
Loop, Parse, var, `,
i := A_LoopField-min, a%i%++
Loop % max-min+1
{
i := A_Index-1, v := i+min
Loop % a%i%
t .= "," v
}
Return SubStr(t,2)
}
GnomeSort(var) {
StringSplit, a, var, `,
i := 2, j := 3
While i <= a0 {
u := i-1
If (a%u% < a%i%)
i := j, j := j+1
Else {
t := a%u%, a%u% := a%i%, a%i% := t
If (--i = 1)
i := j, j++
}
}
Loop % a0
sorted .= "," . a%A_Index%
Return SubStr(sorted,2)
}
InsertionSort(var) {
StringSplit, a, var, `,
Loop % a0-1 {
i := A_Index+1, v := a%i%, j := i-1
While j>0 and a%j%>v
u := j+1, a%u% := a%j%, j--
u := j+1, a%u% := v
}
Loop % a0
sorted .= "," . a%A_Index%
Return SubStr(sorted,2)
}
MergeSort(var) {
StringReplace, t, var, `,,, UseErrorLevel
L := ((t = "") ? 0 : ErrorLevel+1)
If (2 > L)
Return var
StringGetPos, p, var, `,, % "L" L//2
list0 := MergeSort(SubStr(var,1,p))
list1 := MergeSort(SubStr(var,p+2))
If (list0 = "")
Return list1
Else If (list1 = "")
Return list0
list := list0
i0 := (p0 := InStr(list,",",0,i:=p0+1)) ? SubStr(list,i,p0-i) : SubStr(list,i)
list := list1
i1 := (p1 := InStr(list,",",0,i:=p1+1)) ? SubStr(list,i,p1-i) : SubStr(list,i)
Loop {
i := i0>i1
list .= "," i%i%
If (p%i%) {
list := list%i%
i%i% := (p%i% := InStr(list,",",0,i:=p%i%+1)) ? SubStr(list,i,p%i%-i) : SubStr(list,i)
}
Else {
i ^= 1
rtv := SubStr(list "," i%i% (p%i% ? "," SubStr(list%i%,p%i%+1) : ""), 2)
}
}
Return rtv
}
PermutationSort(var) {
static a:="a",v:="v"
StringSplit, a, var, `,
v0 := a0
Loop %v0%
v%A_Index% := A_Index
unsorted := 0
Loop % %a%0-1 {
i := %v%%A_Index%, j := A_Index+1, j := %v%%j%
If (%a%%i% > %a%%j%)
unSorted := 1
}
While unSorted {
i := %v%0, i1 := i-1
While %v%%i1% >= %v%%i% {
--i, --i1
IfLess i1,1, Return 1
}
j := %v%0
While %v%%j% <= %v%%i1%
--j
t := %v%%i1%, %v%%i1% := %v%%j%, %v%%j% := t, j := %v%0
While i < j
t := %v%%i%, %v%%i% := %v%%j%, %v%%j% := t, ++i, --j
unsorted := 0
Loop % %a%0-1 {
i := %v%%A_Index%, j := A_Index+1, j := %v%%j%
If (%a%%i% > %a%%j%)
unSorted := 1
}
}
Loop % a0
i := v%A_Index%, sorted .= "," . a%i%
Return SubStr(sorted,2)
}
QuickSort(var)
{
StringSplit, list, var, `,
If (list0 <= 1)
Return list
pivot := list1
Loop, Parse, var, `,
{
If (A_LoopField < pivot)
less .= "," . A_LoopField
Else If (A_LoopField > pivot)
more .= "," . A_LoopField
Else
pivotlist .= "," . A_LoopField
}
less := QuickSort(substr(less,2))
more := QuickSort(substr(more,2))
Return substr(less,2) . pivotList . more
}
SelectionSort(var) {
StringSplit, a, var, `,
Loop % a0-1 {
i := A_Index, mn := a%i%, j := m := i
Loop % a0-i {
j++
If (a%j% < mn)
mn := a%j%, m := j
}
t := a%i%, a%i% := a%m%, a%m% := t
}
Loop % a0
sorted .= "," . a%A_Index%
Return SubStr(sorted,2)
}
ShellSort(var) {
StringSplit, a, var, `,
inc := a0
While inc:=round(inc/2.2)
Loop % a0-inc {
i := A_Index+inc, t := a%i%, j := i, k := j-inc
While j > inc && a%k% > t
a%j% := a%k%, j := k, k -= inc
a%j% := t
}
Loop % a0
s .= "," . a%A_Index%
Return SubStr(s,2)
}
BuiltInSort(var) {
Sort, var, N D`,
Return var
}
FreeBASIC
#Macro sort_1(sortname)
Rset buffer, #sortname
Print buffer;
copy_array(rev(), sort())
t1 = Timer
sortname(sort())
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec";
copy_array(ran(), sort())
t1 = Timer
sortname(sort())
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec";
t1 = Timer
sortname(sort())
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec";
copy_array(eq(), sort())
t1 = Timer
sortname(sort())
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec"
#EndMacro
#Macro sort_2(sortname)
Rset buffer, #sortname
Print buffer;
copy_array(rev(), sort())
t1 = Timer
sortname(sort(), Lbound(sort), Ubound(sort))
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec";
copy_array(ran(), sort())
t1 = Timer
sortname(sort(), Lbound(sort), Ubound(sort))
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec";
t1 = Timer
sortname(sort(), Lbound(sort), Ubound(sort))
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec";
copy_array(eq(),sort())
t1 = Timer
sortname(sort(), Lbound(sort), Ubound(sort))
t2 = Timer - t1
Print Using " ###.###&"; t2; " sec"
#EndMacro
Sub bubbleSort(array() As Double)
Dim As Integer i, lb = Lbound(array), ub = Ubound(array)
For p1 As Uinteger = 0 To ub - 1
For p2 As Uinteger = p1 + 1 To ub
'change >= to > , don't swap if they are equal
If (array(p1)) > (array(p2)) Then Swap array(p1), array(p2)
Next p2
Next p1
For i = lb To ub - 1
If array(i) > array(i + 1) Then Beep
Next
End Sub
Sub exchangeSort(array() As Double)
Dim As Uinteger i, j, min, ub = Ubound(array)
For i = 0 To ub
min = i
For j = i+1 To ub
If (array(j) < array(min)) Then min = j
Next j
If min > i Then Swap array(i), array(min)
Next i
End Sub
Sub insertionSort(array() As Double)
Dim As Uinteger ub = Ubound(array)
Dim As Uinteger i, j, temp, temp2
For i = 1 To ub
temp = array(i)
temp2 = temp
j = i
While j >= 1 Andalso array(j-1) > temp2
array(j) = array(j - 1)
j -= 1
Wend
array(j) = temp
Next i
End Sub
Sub siftdown(hs() As Double, inicio As Ulong, final As Ulong)
Dim As Ulong root = inicio
Dim As Long lb = Lbound(hs)
While root * 2 + 1 <= final
Dim As Ulong child = root * 2 + 1
If (child + 1 <= final) Andalso (hs(lb + child) < hs(lb + child + 1)) Then child += 1
If hs(lb + root) < hs(lb + child) Then
Swap hs(lb + root), hs(lb + child)
root = child
Else
Return
End If
Wend
End Sub
Sub heapSort(array() As Double)
Dim As Long lb = Lbound(array)
Dim As Ulong count = Ubound(array) - lb + 1
Dim As Long inicio = (count - 2) \ 2
Dim As Ulong final = count - 1
While inicio >= 0
siftdown(array(), inicio, final)
inicio -= 1
Wend
While final > 0
Swap array(lb + final), array(lb)
final -= 1
siftdown(array(), 0, final)
Wend
End Sub
Sub shellSort(array() As Double)
Dim As Uinteger lb = Lbound(array), ub = Ubound(array)
Dim As Uinteger i, inc = ub - lb
Dim As Boolean done
Do
inc = Int(inc / 2.2)
If inc < 1 Then inc = 1
Do
done = false
For i = lb To ub - inc
' reemplace "<" con ">" para ordenación descendente
If array(i) > array(i + inc) Then
Swap array(i), array(i + inc)
done = true
End If
Next i
Loop Until done = false
Loop Until inc = 1
End Sub
Sub quickSort(array() As Double, l As Integer, r As Integer)
Dim As Uinteger size = r - l +1
If size < 2 Then Exit Sub
Dim As Integer i = l, j = r
Dim As Double pivot = array(l + size \ 2)
Do
While array(i) < pivot
i += 1
Wend
While pivot < array(j)
j -= 1
Wend
If i <= j Then
Swap array(i), array(j)
i += 1
j -= 1
End If
Loop Until i > j
If l < j Then quickSort(array(), l, j)
If i < r Then quickSort(array(), i, r)
End Sub
Sub rapidSort (array()As Double, inicio As Integer, final As Integer)
Dim As Integer n, wert, nptr, arr, rep
Dim As Integer LoVal = array(inicio), HiVal = array(final)
For n = inicio To final
If LoVal> array(n) Then LoVal = array(n)
If HiVal< array(n) Then HiVal = array(n)
Next
Redim SortArray(LoVal To HiVal) As Double
For n = inicio To final
wert = array(n)
SortArray(wert) += 1
Next
nptr = inicio-1
For arr = LoVal To HiVal
rep = SortArray(arr)
For n = 1 To rep
nptr += 1
array(nptr) = arr
Next
Next
Erase SortArray
End Sub
Sub copy_array(s() As Double, d() As Double)
For x As Integer = Lbound(s) To Ubound(s)
d(x) = s(x)
Next
End Sub
Dim As Integer x, max = 1e5
Dim As Double t1, t2, ran(0 To max), sort(0 To max), rev(0 To max), eq(0 To max)
Dim As String buffer = Space(14)
Cls
' fill ran() with random numbers and eq() with same number
For x = 0 To max
ran(x) = Rnd
rev(x) = ran(x) ' make reverse array equal to random array
eq(x) = 1/3
Next x
For x = Lbound(rev) To (Ubound(rev) \ 2)
Swap rev(x), rev(Ubound(rev) - x)
Next x
Print !"Test times in sec\nArray size ="; max
Print !"\n *Reversed* *Random* *Sorted* *All ones*"
sort_1(bubbleSort)
sort_1(exchangeSort)
sort_1(insertionSort)
sort_1(heapSort)
sort_1(shellSort)
sort_2(quickSort)
sort_2(rapidSort)
Sleep
- Output:
Test times in sec Array size = 100000 *Reversed* *Random* *Sorted* *All ones* bubbleSort 31.645 sec 31.560 sec 12.765 sec 12.754 sec exchangeSort 12.706 sec 12.708 sec 12.713 sec 12.700 sec insertionSort 4.724 sec 4.739 sec 0.004 sec 0.004 sec heapSort 0.028 sec 0.029 sec 0.021 sec 0.002 sec shellSort 0.049 sec 0.049 sec 0.003 sec 0.003 sec quickSort 0.013 sec 0.013 sec 0.004 sec 0.005 sec rapidSort 0.004 sec 0.004 sec 0.004 sec 0.007 sec
BBC BASIC
HIMEM = PAGE + 2000000
INSTALL @lib$+"SORTLIB"
INSTALL @lib$+"TIMERLIB"
Sort% = FN_sortinit(0,0)
Timer% = FN_ontimer(1000, PROCtimer, 1)
PRINT "Array size:", 1000, 10000, 100000
@% = &2020A
FOR patt% = 1 TO 4
CASE patt% OF
WHEN 1: PRINT '"Data set to all ones:"
WHEN 2: PRINT '"Data ascending sequence:"
WHEN 3: PRINT '"Data randomly shuffled:"
WHEN 4: PRINT '"Data descending sequence:"
ENDCASE
FOR type% = 1 TO 6
CASE type% OF
WHEN 1: PRINT "Internal (lib)";
WHEN 2: PRINT "Quicksort ";
WHEN 3: PRINT "Radix sort ";
WHEN 4: PRINT "Shellsort ";
WHEN 5: PRINT "Bubblesort ";
WHEN 6: PRINT "Insertion sort";
ENDCASE
FOR power% = 3 TO 5
PROCsorttest(patt%, type%, 10^power%)
NEXT
PRINT
NEXT type%
NEXT patt%
END
DEF PROCsorttest(patt%, type%, size%)
LOCAL a%(), C%, I%
DIM a%(size%-1)
CASE patt% OF
WHEN 1: a%() = 1 : a%() = 1
WHEN 2: FOR I% = 0 TO size%-1 : a%(I%) = I% : NEXT
WHEN 3: FOR I% = 0 TO size%-1 : a%(I%) = I% : NEXT
C% = RND(-123456) : REM Seed
FOR I% = size% TO 2 STEP -1 : SWAP a%(I%-1),a%(RND(I%)-1) : NEXT
WHEN 4: FOR I% = 0 TO size%-1 : a%(I%) = size%-1-I% : NEXT
ENDCASE
Start% = TIME
ON ERROR LOCAL PRINT , " >100.00" ; : ENDPROC
CASE type% OF
WHEN 1: C% = size% : CALL Sort%, a%(0)
WHEN 2: PROCquicksort(a%(), 0, size%)
WHEN 3: PROCradixsort(a%(), size%, 10)
WHEN 4: PROCshellsort(a%(), size%)
WHEN 5: PROCbubblesort(a%(), size%)
WHEN 6: PROCinsertionsort(a%(), size%)
ENDCASE
PRINT , (TIME - Start%)/100;
FOR I% = 0 TO size%-2
IF a%(I%) > a%(I%+1) ERROR 100, "Sort failed!"
NEXT
ENDPROC
DEF PROCtimer
Start% += 0
IF (TIME - Start%) > 10000 ERROR 111, ""
ENDPROC
DEF PROCbubblesort(a%(), n%)
LOCAL i%, l%
REPEAT
l% = 0
FOR i% = 1 TO n%-1
IF a%(i%-1) > a%(i%) THEN
SWAP a%(i%-1),a%(i%)
l% = i%
ENDIF
NEXT
n% = l%
UNTIL l% = 0
ENDPROC
DEF PROCinsertionsort(a%(), n%)
LOCAL i%, j%, t%
FOR i% = 1 TO n%-1
t% = a%(i%)
j% = i%
WHILE j%>0 AND t%<a%(ABS(j%-1))
a%(j%) = a%(j%-1)
j% -= 1
ENDWHILE
a%(j%) = t%
NEXT
ENDPROC
DEF PROCquicksort(a%(), s%, n%)
LOCAL l%, p%, r%, t%
IF n% < 2 THEN ENDPROC
t% = s% + n% - 1
l% = s%
r% = t%
p% = a%((l% + r%) DIV 2)
REPEAT
WHILE a%(l%) < p% l% += 1 : ENDWHILE
WHILE a%(r%) > p% r% -= 1 : ENDWHILE
IF l% <= r% THEN
SWAP a%(l%), a%(r%)
l% += 1
r% -= 1
ENDIF
UNTIL l% > r%
IF s% < r% PROCquicksort(a%(), s%, r% - s% + 1)
IF l% < t% PROCquicksort(a%(), l%, t% - l% + 1 )
ENDPROC
DEF PROCshellsort(a%(), n%)
LOCAL h%, i%, j%, k%
h% = n%
WHILE h%
IF h% = 2 h% = 1 ELSE h% DIV= 2.2
FOR i% = h% TO n% - 1
k% = a%(i%)
j% = i%
WHILE j% >= h% AND k% < a%(ABS(j% - h%))
a%(j%) = a%(j% - h%)
j% -= h%
ENDWHILE
a%(j%) = k%
NEXT
ENDWHILE
ENDPROC
DEF PROCradixsort(a%(), n%, r%)
LOCAL d%, e%, i%, l%, m%, b%(), bucket%()
DIM b%(DIM(a%(),1)), bucket%(r%-1)
FOR i% = 0 TO n%-1
IF a%(i%) < l% l% = a%(i%)
IF a%(i%) > m% m% = a%(i%)
NEXT
a%() -= l%
m% -= l%
e% = 1
WHILE m% DIV e%
bucket%() = 0
FOR i% = 0 TO n%-1
bucket%(a%(i%) DIV e% MOD r%) += 1
NEXT
FOR i% = 1 TO r%-1
bucket%(i%) += bucket%(i% - 1)
NEXT
FOR i% = n%-1 TO 0 STEP -1
d% = a%(i%) DIV e% MOD r%
bucket%(d%) -= 1
b%(bucket%(d%)) = a%(i%)
NEXT
a%() = b%()
e% *= r%
ENDWHILE
a%() += l%
ENDPROC
Output:
Array size: 1000 10000 100000 Data set to all ones: Internal (lib) 0.00 0.01 0.03 Quicksort 0.02 0.27 3.18 Radix sort 0.01 0.05 0.53 Shellsort 0.03 0.36 4.44 Bubblesort 0.00 0.01 0.09 Insertion sort 0.00 0.02 0.26 Data ascending sequence: Internal (lib) 0.00 0.00 0.02 Quicksort 0.02 0.15 1.82 Radix sort 0.02 0.18 2.10 Shellsort 0.03 0.37 4.44 Bubblesort 0.00 0.01 0.09 Insertion sort 0.01 0.03 0.27 Data randomly shuffled: Internal (lib) 0.00 0.02 0.44 Quicksort 0.02 0.26 3.17 Radix sort 0.02 0.17 2.08 Shellsort 0.04 0.73 11.57 Bubblesort 0.69 69.70 >100.00 Insertion sort 0.55 55.54 >100.00 Data descending sequence: Internal (lib) 0.00 0.01 0.10 Quicksort 0.01 0.15 1.90 Radix sort 0.02 0.17 2.06 Shellsort 0.03 0.50 6.39 Bubblesort 0.95 94.77 >100.00 Insertion sort 1.11 >100.00 >100.00
C
(The reference example is Python)
Examples of sorting routines
We can use the codes in the category Sorting Algorithms; since these codes deal with integer arrays, we should change them a little. To accomplish this task I've also renamed them more consistently algorithm_sort; so we have e.g. bubble_sort, quick_sort and so on.
Sequence generators
csequence.h
#ifndef _CSEQUENCE_H
#define _CSEQUENCE_H
#include <stdlib.h>
void setfillconst(double c);
void fillwithconst(double *v, int n);
void fillwithrrange(double *v, int n);
void shuffledrange(double *v, int n);
#endif
csequence.c
#include "csequence.h"
static double fill_constant;
void setfillconst(double c)
{
fill_constant = c;
}
void fillwithconst(double *v, int n)
{
while( --n >= 0 ) v[n] = fill_constant;
}
void fillwithrrange(double *v, int n)
{
int on = n;
while( --on >= 0 ) v[on] = n - on;
}
void shuffledrange(double *v, int n)
{
int on = n;
fillwithrrange(v, n);
while( --n >= 0 ) {
int r = rand() % on;
double t = v[n];
v[n] = v[r];
v[r] = t;
}
}
Write timings
We shall use the code from Query Performance. Since the action is a generic function with a single argument, we need wrappers which encapsule each sorting algorithms we want to test.
writetimings.h
#ifndef _WRITETIMINGS_H
#define _WRITETIMINGS_H
#include "sorts.h"
#include "csequence.h"
#include "timeit.h"
/* we repeat the same MEANREPEAT times, and get the mean; this *should*
give "better" results ... */
#define MEANREPEAT 10.0
#define BUFLEN 128
#define MAKEACTION(ALGO) \
int action_ ## ALGO (int size) { \
ALGO ## _sort(tobesorted, size); \
return 0; }
#define MAKEPIECE(N) { #N , action_ ## N }
int action_bubble(int size);
int action_shell(int size);
int action_quick(int size);
int action_insertion(int size);
int action_merge(int size);
int doublecompare( const void *a, const void *b );
int action_qsort(int size);
int get_the_longest(int *a);
struct testpiece
{
const char *name;
int (*action)(int);
};
typedef struct testpiece testpiece_t;
struct seqdef
{
const char *name;
void (*seqcreator)(double *, int);
};
typedef struct seqdef seqdef_t;
#endif
writetimings.c
#include <stdio.h>
#include <stdlib.h>
#include "writetimings.h"
double *tobesorted = NULL;
const char *bname = "data_";
const char *filetempl = "%s%s_%s.dat";
int datlengths[] = {100, 200, 300, 500, 1000, 5000, 10000, 50000, 100000};
testpiece_t testpieces[] =
{
// MAKEPIECE(bubble),
MAKEPIECE(shell),
MAKEPIECE(merge),
MAKEPIECE(insertion),
MAKEPIECE(quick),
MAKEPIECE(qsort),
{ NULL, NULL }
};
seqdef_t seqdefs[] =
{
{ "c1", fillwithconst },
{ "rr", fillwithrrange },
{ "sr", shuffledrange },
{ NULL, NULL }
};
MAKEACTION(bubble)
MAKEACTION(insertion)
MAKEACTION(quick)
MAKEACTION(shell)
int action_merge(int size)
{
double *res = merge_sort(tobesorted, size);
free(res); /* unluckly this affects performance */
return 0;
}
int doublecompare( const void *a, const void *b )
{
if ( *(const double *)a < *(const double *)b ) return -1;
else return *(const double *)a > *(const double *)b;
}
int action_qsort(int size)
{
qsort(tobesorted, size, sizeof(double), doublecompare);
return 0;
}
int get_the_longest(int *a)
{
int r = *a;
while( *a > 0 ) {
if ( *a > r ) r = *a;
a++;
}
return r;
}
int main()
{
int i, j, k, z, lenmax;
char buf[BUFLEN];
FILE *out;
double thetime;
lenmax = get_the_longest(datlengths);
printf("Bigger data set has %d elements\n", lenmax);
tobesorted = malloc(sizeof(double)*lenmax);
if ( tobesorted == NULL ) return 1;
setfillconst(1.0);
for(i=0; testpieces[i].name != NULL; i++) {
for(j=0; seqdefs[j].name != NULL; j++) {
snprintf(buf, BUFLEN, filetempl, bname, testpieces[i].name,
seqdefs[j].name);
out = fopen(buf, "w");
if ( out == NULL ) goto severe;
printf("Producing data for sort '%s', created data type '%s'\n",
testpieces[i].name, seqdefs[j].name);
for(k=0; datlengths[k] > 0; k++) {
printf("\tNumber of elements: %d\n", datlengths[k]);
thetime = 0.0;
seqdefs[j].seqcreator(tobesorted, datlengths[k]);
fprintf(out, "%d ", datlengths[k]);
for(z=0; z < MEANREPEAT; z++) {
thetime += time_it(testpieces[i].action, datlengths[k]);
}
thetime /= MEANREPEAT;
fprintf(out, "%.8lf\n", thetime);
}
fclose(out);
}
}
severe:
free(tobesorted);
return 0;
}
This code produce several files with the following naming convention:
- data_algorithm_sequence.dat
Where algorithm is one of the following: insertion, merge, shell, quick, qsort (the quicksort in the libc library) (bubble sort became too slow for longest sequences). Sequence is c1 (constant value 1), rr (reverse range), sr (shufled range). These data can be easily plotted by Gnuplot, which can also do fitting. Instead we do our fitting using Polynomial Fitting.
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "polifitgsl.h"
#define MAXNUMOFDATA 100
double x[MAXNUMOFDATA], y[MAXNUMOFDATA];
double cf[2];
int main()
{
int i, nod;
int r;
for(i=0; i < MAXNUMOFDATA; i++)
{
r = scanf("%lf %lf\n", &x[i], &y[i]);
if ( (r == EOF) || (r < 2) ) break;
x[i] = log10(x[i]);
y[i] = log10(y[i]);
}
nod = i;
polynomialfit(nod, 2, x, y, cf);
printf("C0 = %lf\nC1 = %lf\n", cf[0], cf[1]);
return 0;
}
Here we search for a fit with C0+C1x "in the log scale", since we supposed the data, once plotted on a logscale graph, can be fitted by a line. We can use e.g. a shell one-liner to produce the parameters for the line for each data file previously output. In particular I've used the following
for el in *.dat ; do fitdata <$el >${el%.dat}.fd ; done
Plot timings and Figures
Once we have all the ".dat" files and associated ".fd", we can use Gnuplot to draw our data and think about conclusions (we could also use the idea in Plot x, y arrays, but it needs too much enhancements to be usable for this analysis). Here an example of such a draw for a single file (using Gnuplot)
gnuplot> f(x) = C0 + C1*x gnuplot> set logscale xy gnuplot> load 'data_quick_sr_u.fd' gnuplot> set xrange [100:100000] gnuplot> set key left gnuplot> plot 10**f(log10(x)), 'data_quick_sr_u.dat'
(The _u.dat are produced by a modified version of the code in order to write timings in microseconds instead of seconds) We can easily write another shell script/one-liner to produce a single file driver for Gnuplot in order to produce all the graph we can be interested in. These graphs show that the linear (in log scale) fit do not always fit the data... I haven't repeated the tests; the problems are when the sequence length becomes huge; for some algorithm that uses extra memory (like implementation of the merge sort), this could depend on the allocation of the needed memory. Another extraneous factor could be system load (the CLOCK_MONOTONIC used by the timing function is system wide rather than per process, so counting time spent in other processes too?). The "most stable" algorithms seem to be quick sort (but not qsort, which indeed is just the libc quick sort, here not plotted!) and shell sort (except for reversed range).
Conclusion: we should repeat the tests...
C++
#include <algorithm>
#include <chrono>
#include <cstdint>
#include <functional>
#include <iomanip>
#include <iostream>
#include <numeric>
#include <random>
#include <string>
#include <vector>
std::random_device random_device;
std::mt19937 generator(random_device());
int32_t measure_execution_time(const std::function<void(std::vector<int32_t>)>& sort, const std::vector<int32_t>& sequence) {
const auto start_time = std::chrono::high_resolution_clock::now();
sort(sequence);
const auto stop_time = std::chrono::high_resolution_clock::now();
return std::chrono::duration_cast<std::chrono::microseconds>(stop_time - start_time).count();
}
std::vector<int32_t> ones(const int32_t& n) {
std::vector<int32_t> result(n, 1);
return result;
}
std::vector<int32_t> ascending(const int32_t& n) {
std::vector<int32_t> result(n);
std::iota(result.begin(), result.end(), 1);
return result;
}
std::vector<int32_t> random(const int32_t& n) {
std::vector<int32_t> result(n);
std::uniform_int_distribution<int32_t> distribution(1, 10 * n);
for ( int32_t i = 0; i < n; ++i ) {
result[i] = distribution(generator);
}
return result;
}
std::function<void(const std::vector<int32_t>&)> bubble_sort = [](std::vector<int32_t> vec) {
int32_t n = vec.size();
while ( n != 0 ) {
int32_t n2 = 0;
for ( int32_t i = 1; i < n; ++i ) {
if ( vec[i - 1] > vec[i] ) {
const int32_t temp = vec[i];
vec[i] = vec[i - 1];
vec[i - 1] = temp;
n2 = i;
}
}
n = n2;
}
};
std::function<void(const std::vector<int32_t>&)> insertion_sort = [](std::vector<int32_t> vec) {
for ( uint32_t index = 1; index < vec.size(); ++index ) {
const int32_t value = vec[index];
int32_t subIndex = index - 1;
while ( subIndex >= 0 && vec[subIndex] > value ) {
vec[subIndex + 1] = vec[subIndex];
subIndex -= 1;
}
vec[subIndex + 1] = value;
}
};
void quick_sort_recursive(std::vector<int32_t>& vec, const int32_t& first, const int32_t& last) {
if ( last - first < 1 ) {
return;
}
const int32_t pivot = vec[first + ( last - first ) / 2];
int32_t left = first;
int32_t right = last;
while ( left <= right ) {
while ( vec[left] < pivot ) {
left += 1;
}
while ( vec[right] > pivot ) {
right -= 1;
}
if ( left <= right ) {
const int32_t temp = vec[left];
vec[left] = vec[right];
vec[right] = temp;
left += 1;
right -= 1;
}
}
if ( first < right ) {
quick_sort_recursive(vec, first, right);
}
if ( left < last ) {
quick_sort_recursive(vec, left, last);
}
}
std::function<void(const std::vector<int32_t>&)> quick_sort = [](std::vector<int32_t> vec) {
quick_sort_recursive(vec, 0, vec.size() - 1);
};
void counting_sort(const std::vector<int32_t>& vec, const int32_t& exponent) {
const int32_t vec_size = vec.size();
std::vector<int32_t> output(vec_size, 0);
std::vector<int32_t> count(10, 0);
for ( int32_t i = 0; i < vec_size; ++i ) {
const int32_t t = ( vec[i] / exponent ) % 10;
count[t] += 1;
}
for ( int32_t i = 1; i <= 9; ++i ) {
count[i] += count[i - 1];
}
for ( int32_t i = vec_size - 1; i >= 0; --i ) {
const int32_t t = ( vec[i] / exponent ) % 10;
output[count[t] - 1] = vec[i];
count[t] -= 1;
}
}
std::function<void(const std::vector<int32_t>&)> radix_sort = [](std::vector<int32_t> vec) {
const int32_t min = *min_element(vec.begin(), vec.end());
if ( min < 0 ) { // If there are any negative numbers, make all the numbers positive
std::for_each(vec.begin(), vec.end(), [min](int32_t& n) { n -= min; });
}
const int32_t max = *std::max_element(vec.begin(), vec.end());
int32_t exponent = 1;
while ( max / exponent > 0 ) {
counting_sort(vec, exponent);
exponent *= 10;
}
if ( min < 0 ) { // If there were any negative numbers, return the array to its original values
std::for_each(vec.begin(), vec.end(), [min](int32_t& n) { n += min; });
}
};
std::function<void(const std::vector<int32_t>&)> shell_sort = [](std::vector<int32_t> vec) {
for ( int32_t gap : { 701, 301, 132, 57, 23, 10, 4, 1 } ) { // Marcin Ciura's gap sequence
for ( uint32_t i = gap; i < vec.size(); ++i ) {
const int32_t temp = vec[i];
int32_t j = i;
while ( j >= gap && vec[j - gap] > temp ) {
vec[j] = vec[j - gap];
j -= gap;
}
vec[j] = temp;
}
}
};
int main() {
const uint32_t repetitions = 10;
std::vector<uint32_t> lengths = { 1, 10, 100, 1'000, 10'000, 100'000 };
std::vector<std::function<void(const std::vector<int32_t>&)>> sorts =
{ bubble_sort, insertion_sort, quick_sort, radix_sort, shell_sort };
std::vector<std::string> sort_titles = { "Bubble", "Insert", "Quick ", "Radix ", "Shell " };
std::vector<std::string> sequence_titles = { "All Ones", "Ascending", "Random" };
std::vector<std::vector<std::vector<int64_t>>> totals =
{ 3, std::vector { sorts.size(), std::vector<int64_t>(lengths.size(), 0) } };
for ( uint32_t k = 0; k < lengths.size(); ++k ) {
const int32_t n = lengths[k];
std::vector<std::vector<int32_t>> sequences = { ones(n), ascending(n), random(n) };
for ( uint32_t repetition = 0; repetition < repetitions; ++repetition ) {
for ( uint32_t i = 0; i < sequences.size(); ++i ) {
for ( uint32_t j = 0; j < sorts.size(); ++j ) {
totals[i][j][k] += measure_execution_time(sorts[j], sequences[i]);
}
}
}
}
std::cout << "All timings in microseconds." << "\n\n";
std::cout << "Sequence length";
for ( const uint32_t& length : lengths ) {
std::cout << std::setw(10) << length;
}
std::cout << "\n\n";
for ( uint32_t i = 0; i < sequence_titles.size(); ++i ) {
std::cout << " " + sequence_titles[i] + ":" << "\n";
for ( uint32_t j = 0; j < sorts.size(); ++j ) {
std::cout << " " + sort_titles[j] + " ";
for ( uint32_t k = 0; k < lengths.size(); ++k ) {
const int64_t execution_time = totals[i][j][k] / repetitions;
std::cout << std::setw(10) << execution_time;
}
std::cout << "\n";
}
std::cout << "\n\n";
}
}
- Output:
All timings in microseconds. Sequence length 1 10 100 1000 10000 100000 All Ones: Bubble 0 0 0 2 50 492 Insert 0 0 0 4 64 632 Quick 0 0 3 33 441 5466 Radix 0 0 2 19 201 1934 Shell 0 0 2 26 309 3049 Ascending: Bubble 0 0 0 2 51 472 Insert 0 0 0 4 67 616 Quick 0 0 2 20 232 2727 Radix 0 1 5 49 565 6395 Shell 0 0 2 26 308 3059 Random: Bubble 0 0 34 2802 299357 33149458 Insert 0 0 10 751 64170 7267168 Quick 0 0 5 83 1013 12127 Radix 0 1 5 46 528 6185 Shell 0 0 5 122 1467 25568
D
import std.stdio, std.algorithm, std.container, std.datetime,
std.random, std.typetuple;
immutable int[] allOnes, sortedData, randomData;
static this() { // Initialize global Arrays.
immutable size_t arraySize = 10_000;
allOnes = new int[arraySize];
//allOnes[] = 1;
foreach (ref d; allOnes)
d = 1;
sortedData = new int[arraySize];
foreach (immutable i, ref d; sortedData)
d = i;
randomData = new int[arraySize];
foreach (ref d; randomData)
d = uniform(0, int.max);
}
// BubbleSort:
void bubbleSort(T)(T[] list) {
for (int i = list.length - 1; i > 0; i--)
for (int j = i -1; j >= 0; j--)
if (list[i] < list[j])
swap(list[i], list[j]);
}
void allOnesBubble() {
auto data = allOnes.dup;
data.bubbleSort;
assert(data.isSorted);
}
void sortedBubble() {
auto data = sortedData.dup;
data.bubbleSort;
assert(data.isSorted);
}
void randomBubble() {
auto data = randomData.dup;
data.bubbleSort;
assert(data.isSorted);
}
// InsertionSort:
void insertionSort(T)(T[] list) {
foreach (immutable i, currElem; list) {
size_t j = i;
for (; j > 0 && currElem < list[j - 1]; j--)
list[j] = list[j - 1];
list[j] = currElem;
}
}
void allOnesInsertion() {
auto data = allOnes.dup;
data.insertionSort;
assert(data.isSorted);
}
void sortedInsertion() {
auto data = sortedData.dup;
data.insertionSort;
assert(data.isSorted);
}
void randomInsertion() {
auto data = randomData.dup;
data.insertionSort;
assert(data.isSorted);
}
// HeapSort:
void heapSort(T)(T[] data) {
auto h = data.heapify;
while (!h.empty)
h.removeFront;
}
void allOnesHeap() {
auto data = allOnes.dup;
data.heapSort;
assert(data.isSorted);
}
void sortedHeap() {
auto data = sortedData.dup;
data.heapSort;
assert(data.isSorted);
}
void randomHeap() {
auto data = randomData.dup;
data.heapSort;
assert(data.isSorted);
}
// Built-in sort:
void allOnesBuiltIn() {
auto data = allOnes.dup;
data.sort!q{a < b};
assert(data.isSorted);
}
void sortedBuiltIn() {
auto data = sortedData.dup;
data.sort!q{a < b};
assert(data.isSorted);
}
void randomBuiltIn() {
auto data = randomData.dup;
data.sort!q{a < b};
assert(data.isSorted);
}
static void show(in TickDuration[4u] r) {
alias args = TypeTuple!("usecs", int);
writefln(" Bubble Sort: %10d", r[0].to!args);
writefln(" Insertion Sort: %10d", r[1].to!args);
writefln(" Heap Sort: %10d", r[3].to!args);
writefln(" Built-in Sort: %10d", r[2].to!args);
}
void main() {
enum nRuns = 100;
writeln("Timings in microseconds:");
writeln(" Testing against all ones:");
nRuns.benchmark!(allOnesBubble, allOnesInsertion,
allOnesHeap, allOnesBuiltIn).show;
writeln("\n Testing against sorted data.");
nRuns.benchmark!(sortedBubble, sortedInsertion,
sortedHeap, sortedBuiltIn).show;
writeln("\n Testing against random data.");
nRuns.benchmark!(randomBubble, randomInsertion,
randomHeap, randomBuiltIn).show;
}
- Output:
Timings in microseconds: Testing against all ones: Bubble Sort: 7377065 Insertion Sort: 5868 Heap Sort: 25173 Built-in Sort: 34538 Testing against sorted data. Bubble Sort: 7370520 Insertion Sort: 6006 Heap Sort: 18127 Built-in Sort: 176235 Testing against random data. Bubble Sort: 27293705 Insertion Sort: 3762374 Heap Sort: 85053 Built-in Sort: 218268
(With 10,000 elements in each array. A naive HeapSort seems faster than the built-in sort in all three cases.)
Erlang
The sort routines are borrowed from bubble sort, insertion sort and quick sort. Plots by eplot. Bubble sort does ones and ranges best. Insertion sort does reversed ranges best. Quick sort handles shuffled numbers best.
-module( compare_sorting_algorithms ).
-export( [task/0] ).
task() ->
Ns = [100, 1000, 10000],
Lists = [{"ones", fun list_of_ones/1, Ns}, {"ranges", fun list_of_ranges/1, Ns}, {"reversed_ranges", fun list_of_reversed_ranges/1, Ns}, {"shuffleds", fun list_of_shuffleds/1, Ns}],
Sorts = [{bubble_sort, fun bubble_sort:list/1}, {insertion_sort, fun sort:insertion/1}, {iquick_sort, fun quicksort:qsort/1}],
Results = [time_list(X, Sorts) || X <- Lists],
[file:write_file(X++".png", egd_chart:graph(Y, [{x_label, "log N"}, {y_label, "log ms"}])) || {X, Y} <- Results].
list_of_ones( N ) -> [1 || _X <- lists:seq(1, N)].
list_of_ranges( N ) -> [X || X <- lists:seq(1, N)].
list_of_reversed_ranges( N ) -> lists:reverse( list_of_ranges(N) ).
list_of_shuffleds( N ) -> [random:uniform(N) || _X <- lists:seq(1, N)].
time_list( {List, List_fun, Values}, Sorts ) ->
Results = [{Sort, time_sort(Sort_fun, List_fun, Values)} || {Sort, Sort_fun} <- Sorts],
{List, Results}.
time_sort( Sort_fun, List_fun, Values ) ->
[time(Sort_fun, List_fun, X) || X <- Values].
time( Fun, List_fun, N ) ->
{Time, _Result} = timer:tc( fun() -> Fun( List_fun(N) ) end ),
{math:log10(N), math:log10(Time)}.
Go
package main
import (
"log"
"math/rand"
"testing"
"time"
"github.com/gonum/plot"
"github.com/gonum/plot/plotter"
"github.com/gonum/plot/plotutil"
"github.com/gonum/plot/vg"
)
// Step 1, sort routines.
// These functions are copied without changes from the RC tasks Bubble Sort,
// Insertion sort, and Quicksort.
func bubblesort(a []int) {
for itemCount := len(a) - 1; ; itemCount-- {
hasChanged := false
for index := 0; index < itemCount; index++ {
if a[index] > a[index+1] {
a[index], a[index+1] = a[index+1], a[index]
hasChanged = true
}
}
if hasChanged == false {
break
}
}
}
func insertionsort(a []int) {
for i := 1; i < len(a); i++ {
value := a[i]
j := i - 1
for j >= 0 && a[j] > value {
a[j+1] = a[j]
j = j - 1
}
a[j+1] = value
}
}
func quicksort(a []int) {
var pex func(int, int)
pex = func(lower, upper int) {
for {
switch upper - lower {
case -1, 0:
return
case 1:
if a[upper] < a[lower] {
a[upper], a[lower] = a[lower], a[upper]
}
return
}
bx := (upper + lower) / 2
b := a[bx]
lp := lower
up := upper
outer:
for {
for lp < upper && !(b < a[lp]) {
lp++
}
for {
if lp > up {
break outer
}
if a[up] < b {
break
}
up--
}
a[lp], a[up] = a[up], a[lp]
lp++
up--
}
if bx < lp {
if bx < lp-1 {
a[bx], a[lp-1] = a[lp-1], b
}
up = lp - 2
} else {
if bx > lp {
a[bx], a[lp] = a[lp], b
}
up = lp - 1
lp++
}
if up-lower < upper-lp {
pex(lower, up)
lower = lp
} else {
pex(lp, upper)
upper = up
}
}
}
pex(0, len(a)-1)
}
// Step 2.0 sequence routines. 2.0 is the easy part. 2.5, timings, follows.
func ones(n int) []int {
s := make([]int, n)
for i := range s {
s[i] = 1
}
return s
}
func ascending(n int) []int {
s := make([]int, n)
v := 1
for i := 0; i < n; {
if rand.Intn(3) == 0 {
s[i] = v
i++
}
v++
}
return s
}
func shuffled(n int) []int {
return rand.Perm(n)
}
// Steps 2.5 write timings, and 3 plot timings are coded together.
// If write means format and output human readable numbers, step 2.5
// is satisfied with the log output as the program runs. The timings
// are plotted immediately however for step 3, not read and parsed from
// any formated output.
const (
nPts = 7 // number of points per test
inc = 1000 // data set size increment per point
)
var (
p *plot.Plot
sortName = []string{"Bubble sort", "Insertion sort", "Quicksort"}
sortFunc = []func([]int){bubblesort, insertionsort, quicksort}
dataName = []string{"Ones", "Ascending", "Shuffled"}
dataFunc = []func(int) []int{ones, ascending, shuffled}
)
func main() {
rand.Seed(time.Now().Unix())
var err error
p, err = plot.New()
if err != nil {
log.Fatal(err)
}
p.X.Label.Text = "Data size"
p.Y.Label.Text = "microseconds"
p.Y.Scale = plot.LogScale{}
p.Y.Tick.Marker = plot.LogTicks{}
p.Y.Min = .5 // hard coded to make enough room for legend
for dx, name := range dataName {
s, err := plotter.NewScatter(plotter.XYs{})
if err != nil {
log.Fatal(err)
}
s.Shape = plotutil.DefaultGlyphShapes[dx]
p.Legend.Add(name, s)
}
for sx, name := range sortName {
l, err := plotter.NewLine(plotter.XYs{})
if err != nil {
log.Fatal(err)
}
l.Color = plotutil.DarkColors[sx]
p.Legend.Add(name, l)
}
for sx := range sortFunc {
bench(sx, 0, 1) // for ones, a single timing is sufficient.
bench(sx, 1, 5) // ascending and shuffled have some randomness though,
bench(sx, 2, 5) // so average timings on 5 different random sets.
}
if err := p.Save(5*vg.Inch, 5*vg.Inch, "comp.png"); err != nil {
log.Fatal(err)
}
}
func bench(sx, dx, rep int) {
log.Println("bench", sortName[sx], dataName[dx], "x", rep)
pts := make(plotter.XYs, nPts)
sf := sortFunc[sx]
for i := range pts {
x := (i + 1) * inc
// to avoid timing sequence creation, create sequence before timing
// then just copy the data inside the timing loop. copy time should
// be the same regardless of sequence data.
s0 := dataFunc[dx](x) // reference sequence
s := make([]int, x) // working copy
var tSort int64
for j := 0; j < rep; j++ {
tSort += testing.Benchmark(func(b *testing.B) {
for i := 0; i < b.N; i++ {
copy(s, s0)
sf(s)
}
}).NsPerOp()
}
tSort /= int64(rep)
log.Println(x, "items", tSort, "ns") // step 2.5, write timings
pts[i] = struct{ X, Y float64 }{float64(x), float64(tSort) * .001}
}
pl, ps, err := plotter.NewLinePoints(pts) // step 3, plot timings
if err != nil {
log.Fatal(err)
}
pl.Color = plotutil.DarkColors[sx]
ps.Color = plotutil.DarkColors[sx]
ps.Shape = plotutil.DefaultGlyphShapes[dx]
p.Add(pl, ps)
}
- Output:
Step 4, conclusions about relative performance of the sorting routines made based on the plots.
The plots show differences in best and worse case performance for the various data sets. Bubble and insertion sorts show very good best case performance with all one and ascending sequences, beating quicksort. Quicksort shows best case performance with the ascending sequence but worst case performance with the all one sequence.
On random data (triangles) insertion and bubble sort show worse performance than quicksort.
Haskell
import Data.Time.Clock
import Data.List
type Time = Integer
type Sorter a = [a] -> [a]
-- Simple timing function (in microseconds)
timed :: IO a -> IO (a, Time)
timed prog = do
t0 <- getCurrentTime
x <- prog
t1 <- x `seq` getCurrentTime
return (x, ceiling $ 1000000 * diffUTCTime t1 t0)
-- testing sorting algorithm on a given set
test :: [a] -> Sorter a -> IO [(Int, Time)]
test set srt = mapM (timed . run) ns
where
ns = take 15 $ iterate (\x -> (x * 5) `div` 3) 10
run n = pure $ length $ srt (take n set)
-- sample sets
constant = repeat 1
presorted = [1..]
random = (`mod` 100) <$> iterate step 42
where
step x = (x * a + c) `mod` m
(a, c, m) = (1103515245, 12345, 2^31-1)
As a result of testing we get the list of tuples: length of a list and time in microseconds:
λ> test ones sort [(10,9),(16,7),(26,5),(43,5),(71,6),(118,8),(196,12),(326,18),(543,28),(905,41),(1508,68),(2513,108),(4188,191),(6980,303),(11633,484)] λ> test rand sort [(10,8),(16,7),(26,7),(43,9),(71,15),(118,24),(196,43),(326,82),(543,136),(905,270),(1508,482),(2513,1004),(4188,1926),(6980,4612),(11633,7286)]
Different sorting methods:
-- Naive quick sort
qsort :: Ord a => Sorter a
qsort [] = []
qsort (h:t) = qsort (filter (< h) t) ++ [h] ++ qsort (filter (>= h) t)
-- Bubble sort
bsort :: Ord a => Sorter a
bsort s = case _bsort s of
t | t == s -> t
| otherwise -> bsort t
where _bsort (x:x2:xs) | x > x2 = x2:_bsort (x:xs)
| otherwise = x :_bsort (x2:xs)
_bsort s = s
-- Insertion sort
isort :: Ord a => Sorter a
isort = foldr insert []
Finally, charting routines and the task implementation:
-- chart appears to be logarithmic scale on both axes
barChart :: Char -> [(Int, Time)] -> [String]
barChart ch lst = bar . scale <$> lst
where
scale (x,y) = (x, round $ (3*) $ log $ fromIntegral y)
bar (x,y) = show x ++ "\t" ++ replicate y ' ' ++ [ch]
over :: String -> String -> String
over s1 s2 = take n $ zipWith f (pad s1) (pad s2)
where
f ' ' c = c
f c ' ' = c
f y _ = y
pad = (++ repeat ' ')
n = length s1 `max` length s2
comparison :: Ord a => [Sorter a] -> [Char] -> [a] -> IO ()
comparison sortings chars set = do
results <- mapM (test set) sortings
let charts = zipWith barChart chars results
putStrLn $ replicate 50 '-'
mapM_ putStrLn $ foldl1 (zipWith over) charts
putStrLn $ replicate 50 '-'
let times = map (fromInteger . snd) <$> results
let ratios = mean . zipWith (flip (/)) (head times) <$> times
putStrLn "Comparing average time ratios:"
mapM_ putStrLn $ zipWith (\r s -> [s] ++ ": " ++ show r) ratios chars
where
mean lst = sum lst / genericLength lst
main = do
putStrLn "comparing on list of ones"
run ones
putStrLn "\ncomparing on presorted list"
run seqn
putStrLn "\ncomparing on shuffled list"
run rand
where
run = comparison [sort, isort, qsort, bsort] "siqb"
λ> main comparing on list of ones -------------------------------------------------- 10 is b q 16 is b q 26 s b q 43 si b q 71 si b q 118 si b q 196 si b q 326 si b q 543 s i b q 905 s i b q 1508 s i b q 2513 s i b q 4188 s i b q 6980 s i b q 11633 s i b q -------------------------------------------------- Comparing average time ratios: s: 1.0 i: 1.9768226698141058 q: 4948.447011286744 b: 8.648711819912956 comparing on presorted list -------------------------------------------------- 10 isb q 16 s b q 26 s b q 43 i s b q 71 is b q 118 s b q 196 s b q 326 si b q 543 si b q 905 si b q 1508 si b q 2513 si b q 4188 s i b q 6980 s i b q 11633 s i b q -------------------------------------------------- Comparing average time ratios: s: 1.0 i: 1.2828547504398033 q: 2586.058542372048 b: 4.478306385307422 comparing on shuffled list -------------------------------------------------- 10 i qs 16 is q b 26 s q b 43 is q b 71 s q b 118 si q b 196 si q b 326 s i b 543 s qi b 905 s i b 1508 s q i b 2513 s q i b 4188 s q i b 6980 s q i b 11633 s q i b -------------------------------------------------- Comparing average time ratios: s: 1.0 i: 33.0167854766955 q: 4.778965210071694 b: 920.9348663725772
We see that well known Haskell meme -- naive quicksort, is total mess on degenerate cases, and it does much better in general, still being significantly more slow then standard implementation. This tests were done in GHCi. Lazy Haskell program may be drastically rewritten and optimized during compilation. Let's see how it goes after compilation:
$ ghc -O2 CompareSort.hs [1 of 1] Compiling Main ( CompareSort.hs, CompareSort.o ) Linking CompareSort ... $ ./CompareSort comparing on list of ones -------------------------------------------------- 10 i q s 16 s q 26 i s q 43 bs i q 71 ibs q 118 ibs q 196 ib s q 326 i bs q 543 bis q 905 i bs q 1508 ib s q 2513 ibs q 4188 ib s q 6980 si q 11633 si q -------------------------------------------------- Comparing average time ratios: s: 1.0 i: 0.9148588587463226 q: 751.3527462449417 b: 0.774109602468018 comparing on presorted list -------------------------------------------------- 10 i s 16 s q 26 s q 43 i s q 71 s q 118 sb q 196 is q 326 isb q 543 sb q 905 sb i q 1508 is q 2513 sb q 4188 is q 6980 ibs q 11633 s q -------------------------------------------------- Comparing average time ratios: s: 1.0 i: 1.114052564981571 q: 577.8734457264803 b: 1.1171025867573912 comparing on shuffled list -------------------------------------------------- 10 iqs 16 is 26 isb 43 sq b 71 si b 118 si b 196 s i b 326 sq i b 543 s i b 905 sq i b 1508 s q i b 2513 s q i b 4188 s q i b 6980 s q i b 11633 s q i b -------------------------------------------------- Comparing average time ratios: s: 1.0 i: 29.346876854773274 q: 1.3750763918038253 b: 71.47503300525689
Even though quicksort still sucks on degenerate lists, it does really much better when compiled. Bubble sort had also improved it's rate, in contrast to insertion sort which didn't gain anything from compilation.
J
NB. extracts from other rosetta code projects
ts=: 6!:2, 7!:2@]
radix =: 3 : 0
256 radix y
:
a=. #{. z =. x #.^:_1 y
e=. (-a) {."0 b =. i.x
x#.1{::(<:@[;([: ; (b, {"1) <@}./. e,]))&>/^:a [ z;~a-1
NB. , ([: ; (b, {:"1) <@(}:"1@:}.)/. e,])^:(#{.z) y,.z
)
bubble=: (([ (<. , >.) {.@]) , }.@])/^:_
insertion=:((>: # ]) , [ , < #])/
sel=: 1 : 'x # ['
quick=: 3 : 0
if. 1 >: #y do. y
else.
e=. y{~?#y
(quick y <sel e),(y =sel e),quick y >sel e
end.
)
gaps =: [: }: 1 (1+3*])^:(> {:)^:a:~ #
insert =: (I.~ {. ]) , [ , ] }.~ I.~
gapinss =: #@] {. ,@|:@(] insert//.~ #@] $ i.@[)
shell =: [: ; gapinss &.>/@(< ,~ ]&.>@gaps)
builtin =: /:~
NB. characterization of the sorting algorithms.
sorts =: bubble`insertion`shell`quick`radix`builtin
generators =: #&1`(i.@-)`(?.~) NB. data generators
round =: [: <. 1r2&+
ll =: (<_1 0)&{ NB. verb to extract lower left which holds ln data length
lc =: (<_1 1)&{ NB. verb to fetch lower center which holds most recent time
NB. maximum_time characterize ln_start_size
NB. characterize returns a rank 4 matrix with successive indexes for
NB. algorithm, input arrangement, max number of tests in group, length time space
characterize =: 4 : 0
max_time =. x
start =. 1 3{.<:y
for_sort. sorts do.
for_generator. generators do. NB. limit time and paging prevention
t =: }. (, (, [: ts 'sort@.0 (generator@.0)' , ":@round@^)@>:@ll) ^: ((lc < max_time"_) *. ll < 17"_) ^:_ start
if. generator -: {.generators do.
g =. ,:t
else.
g =. g,t
end.
end.
if. sort -: {.sorts do.
s =. ,:g
else.
s =. s,g
end.
end.
)
NB. character cell graphics
NB. From j phrases 10E. Approximation
d3=: 1&,.@[ %.~ ] NB. a and b such that y is approx. a + b*x
NB. domain and range 0 to 14.
D=:14
plot =: 1 : '(=/ round@(u&.(*&(D%<:y))))i.y' NB. function plot size
points =: 4 : '1(<"1|:|.round y*D%~<:x)}0$~2#x' NB. size points x,:y
show =: [: |. [: '0'&~:@{:} ' ' ,: ":
plt =: 3 : 0
30 plt y NB. default size 30
:
n =. >:i.-# experiments =. <@(#~"1 (0&<)@{.)"2 y
pts =. n +./ .*x&points@>experiments
coef =. d3/@>experiments
(_*pts) + n +./ .*1 0 2|:coef&(p."1) plot x
)
a =: 1 characterize 5 $a NB. a has rank 4 6 3 13 3 'l t s' =: |:a NB. transpose moves length time space to leading dimension l =: |: <: l NB. transpose restores order t =: |: 12 +^. t NB. choose arbitrary time units so that ^. time is positive s =: |: ^. s NB. ln space NB. 6 groups of sort methods with 3 arrangements of data ---> exponentially increasing data lengths, 6j2":t NB. ln time negative infinity indicates avoided experiment 3.83 4.80 5.89 7.15 8.65 10.18 11.90 13.75 __ __ __ __ __ 8.77 10.90 13.13 __ __ __ __ __ __ __ __ __ __ 8.70 10.87 13.11 __ __ __ __ __ __ __ __ __ __ 3.91 5.43 7.13 8.90 10.76 12.73 __ __ __ __ __ __ __ 3.99 5.63 7.42 9.21 11.13 13.06 __ __ __ __ __ __ __ 4.14 5.72 7.58 9.37 11.30 13.26 __ __ __ __ __ __ __ 5.56 6.75 7.90 9.05 10.27 11.60 13.13 __ __ __ __ __ __ 5.61 6.88 8.05 9.40 10.84 12.48 __ __ __ __ __ __ __ 5.67 6.93 8.09 9.43 10.89 12.48 __ __ __ __ __ __ __ 1.95 1.99 2.19 2.46 2.98 3.66 4.63 5.54 6.60 7.61 8.70 9.81 10.99 6.06 7.13 8.09 9.09 10.10 11.10 12.12 __ __ __ __ __ __ 6.09 7.17 8.10 9.11 10.11 11.12 12.14 __ __ __ __ __ __ 3.25 3.33 3.55 4.06 4.77 5.60 6.72 7.75 8.75 10.11 11.21 12.22 __ 3.37 3.87 4.19 4.72 5.53 6.49 7.84 9.29 10.71 11.78 12.88 __ __ 3.42 4.00 4.43 5.07 5.93 7.07 8.06 9.76 10.96 12.10 __ __ __ 0.38 0.38 0.58 1.02 1.68 2.68 3.45 4.42 5.42 6.51 7.64 8.86 9.87 0.49 0.58 0.96 1.55 2.34 3.11 4.31 5.82 7.43 8.70 9.75 10.75 11.75 1.40 2.01 2.88 3.87 4.92 5.92 7.05 8.18 9.45 10.91 12.01 __ __
This display is no less than a bar chart and, frankly, suffices but for the curve fit requirement.
NB. algorithms: bubble 6, insertion 5, shell 4, quick 3, radix 2, builtin 1 NB. rows: log time NB. cols: log size NB. data is all 1 show 30 plt l ,: & (0&{)"2 t 5 4 _ 2 2 4 2 5 _ 6 2 _ 4 6 2 4 _ _ 3 5 _ 6 2 3 6 _ _ 3 1 _ 4 2 3 3 1 _ _ _ 3 1 1 6 2 _ _ 1 _ 2 3 1 _ _ 2 _ _ _ 4 2 3 1 _ 5 6 2 _ 3 _ _ 4 _ _ 2 3 1 _ _ 3 _ _ 5 6 2 3 1 4 _ _ 3 _ 1 4 _ 2 3 1 _ _ 6 2 _ 3 3 1 1 5 6 2 3 _ 1 _ 2 _ 3 _ 1 5 6 _ _ 3 1 _ 6 2 3 _ 1 2 _ _ 1 _ 2 _ 3 3 1 2 3 1 _ 3 _ 3 _ _ 1 3 1 1 NB. data is reversed integer list show 30 plt l ,: & (1&{)"2 t 6 4 3 1 5 4 3 2 1 _ _ 4 3 _ 2 1 _ 3 2 1 6 4 _ 2 _ 1 3 _ _ _ _ 2 1 6 4 3 _ _ 1 _ 2 1 6 _ 3 2 _ _ 2 _ 1 6 1 2 _ _ 5 2 1 3 2 _ 1 _ 4 _ 2 _ 3 _ 1 3 5 2 _ 1 4 _ 2 1 _ 4 5 2 _ 1 _ 1 5 _ 2 1 _ 5 _ 2 1 2 1 _ 2 2 _ 2 1 _ _ 1 _ 1 1 NB. data is random show 30 plt l ,: & (2&{)"2 t 6 5 4 3 2 1 _ 4 3 2 1 _ 5 4 3 2 1 _ 3 2 1 6 5 4 _ _ _ 4 3 2 1 _ _ _ _ _ 1 6 4 3 1 1 _ 2 1 6 _ 3 _ _ _ 2 1 6 1 2 1 _ 5 _ 1 _ 3 _ 2 1 _ 4 5 2 1 3 _ 5 2 _ 1 _ 3 4 2 _ 2 _ _ 4 _ 1 5 2 _ _ 1 5 _ 2 _ 2 1 2 _ 2 _ 1 1 1 1
The first version of the code set only a time limit. The builtin sort violated this only when the data overflowed RAM into virtual space, causing a large jump in time affecting also the next data set as the OS restored itself. The timing might be interesting for some other exercise. Here, a maximum data size test was inserted. Arbitrary time is the reasonable choice without details of the J interpreter nor of specific hardware. The radix sort involves putting data directly into the right spot. It is quick!
The data fit curves of the character cell graph were combined with GCD +. function. This explains "1"s or other strange values where these curves intersect. Finally the scatter plots were multiplied by infinity and added to the best fit curves. The points didn't show up well using the same values as the curves.
Java
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.stream.IntStream;
import java.util.stream.Stream;
public final class ComparingSortingAlgorithmsPerformance {
public static void main(String[] args) {
final int repetitions = 10;
List<Integer> lengths = List.of( 1, 10, 100, 1_000, 10_000, 100_000 );
List<Consumer<int[]>> sorts = List.of( bubbleSort, insertionSort, quickSort, radixSort, shellSort );
// Allow the JVM to compile the sort functions before timings start
for ( Consumer<int[]> sort : sorts ) {
sort.accept( new int[] { 1 } );
}
List<String> sortTitles = List.of( "Bubble", "Insert", "Quick ", "Radix ", "Shell " );
List<String> sequenceTitles = List.of( "All Ones", "Ascending", "Random" );
long[][][] totals = new long[sequenceTitles.size()][sorts.size()][lengths.size()];
for ( int k = 0; k < lengths.size(); k++ ) {
final int n = lengths.get(k);
List<int[]> sequences = List.of( ones.apply(n), ascending.apply(n), random.apply(n) );
for ( int repetition = 0; repetition < repetitions; repetition++ ) {
for ( int i = 0; i < sequences.size(); i++ ) {
for ( int j = 0; j < sorts.size(); j++ ) {
totals[i][j][k] += measureExecutionTime(sorts.get(j), sequences.get(i));
}
}
}
}
System.out.println("All timings in microseconds." + System.lineSeparator());
System.out.print("Sequence length");
for ( int length : lengths ) {
System.out.print(String.format("%8d ", length));
}
System.out.println(System.lineSeparator());
for ( int i = 0; i < sequenceTitles.size(); i++ ) {
System.out.println(" " + sequenceTitles.get(i) + ":");
for ( int j = 0; j < sorts.size(); j++ ) {
System.out.print(" " + sortTitles.get(j) + " ");
for ( int k = 0; k < lengths.size(); k++ ) {
final long executionTime = totals[i][j][k] / repetitions;
System.out.print(String.format("%8d ", executionTime));
}
System.out.println();
}
System.out.println(System.lineSeparator());
}
}
private static Consumer<int[]> bubbleSort = array -> {
int n = array.length;
while ( n != 0 ) {
int n2 = 0;
for ( int i = 1; i < n; i++ ) {
if ( array[i - 1] > array[i] ) {
final int temp = array[i];
array[i] = array[i - 1];
array[i - 1] = temp;
n2 = i;
}
}
n = n2;
}
};
private static Consumer<int[]> insertionSort = array -> {
for ( int index = 1; index < array.length; index++ ) {
final int value = array[index];
int subIndex = index - 1;
while ( subIndex >= 0 && array[subIndex] > value ) {
array[subIndex + 1] = array[subIndex];
subIndex -= 1;
}
array[subIndex + 1] = value;
}
};
private static Consumer<int[]> quickSort = array -> {
final class LocalClass {
private static void quickSortRecursive(int[] array, int first, int last) {
if ( last - first < 1 ) {
return;
}
final int pivot = array[first + ( last - first ) / 2];
int left = first;
int right = last;
while ( left <= right ) {
while ( array[left] < pivot ) {
left += 1;
}
while ( array[right] > pivot ) {
right -= 1;
}
if ( left <= right ) {
final int temp = array[left];
array[left] = array[right];
array[right] = temp;
left += 1;
right -= 1;
}
}
if ( first < right ) {
quickSortRecursive(array, first, right);
}
if ( left < last ) {
quickSortRecursive(array, left, last);
}
}
}
LocalClass.quickSortRecursive(array, 0, array.length - 1);
};
private static Consumer<int[]> radixSort = array -> {
final class LocalClass {
private static void countingSort(int[] array, int exponent) {
final int n = array.length;
int[] output = new int[n];
int[] count = new int[10];
for ( int i = 0; i < n; i++ ) {
final int t = ( array[i] / exponent ) % 10;
count[t] += 1;
}
for ( int i = 1; i <= 9; i++ ) {
count[i] += count[i - 1];
}
for ( int i = n - 1; i >= 0; i-- ) {
final int t = ( array[i] / exponent ) % 10;
output[count[t] - 1] = array[i];
count[t] -= 1;
}
for ( int i = 0; i < n; i++ ) {
array[i] = output[i];
}
}
}
final int min = Arrays.stream(array).min().getAsInt();
if ( min < 0 ) { // If there are any negative numbers, make all the numbers positive
array = Arrays.stream(array).map( i -> i - min).toArray();
}
final int max = Arrays.stream(array).max().getAsInt();
int exponent = 1;
while ( max / exponent > 0 ) {
LocalClass.countingSort(array, exponent);
exponent *= 10;
}
if ( min < 0 ) { // If there were any negative numbers, return the array to its original values
array = Arrays.stream(array).map( i -> i + min).toArray();
}
};
private static Consumer<int[]> shellSort = array -> {
for ( int gap : new int[] { 701, 301, 132, 57, 23, 10, 4, 1 } ) { // Marcin Ciura's gap sequence
for ( int i = gap; i < array.length; i++ ) {
final int temp = array[i];
int j = i;
while ( j >= gap && array[j - gap] > temp ) {
array[j] = array[j - gap];
j -= gap;
}
array[j] = temp;
}
}
};
private static Function<Integer, int[]> ones =
n -> Stream.generate( () -> 1 ).limit(n).mapToInt(Integer::valueOf).toArray();
private static Function<Integer, int[]> ascending = n -> IntStream.rangeClosed(1, n).toArray();
private static Function<Integer, int[]> random = n -> new Random().ints(1, 10 * n).limit(n).toArray();
private static long measureExecutionTime(Consumer<int[]> sort, int[] sequence) {
final long startTime = System.nanoTime();
sort.accept(sequence);
return ( System.nanoTime() - startTime ) / 1_000; // microseconds
}
}
- Output:
All timings in microseconds. Sequence length 1 10 100 1000 10000 100000 All Ones: Bubble 0 0 0 3 7 37 Insert 0 0 2 10 25 15 Quick 0 1 4 23 176 1323 Radix 5 8 17 25 334 663 Shell 0 0 8 60 92 146 Ascending: Bubble 0 0 0 2 7 37 Insert 0 0 2 10 26 14 Quick 0 0 3 19 91 918 Radix 3 8 24 55 847 2833 Shell 0 0 8 57 110 145 Random: Bubble 0 0 9 352 9152 1108542 Insert 0 0 2 8 24 15 Quick 0 0 2 20 101 980 Radix 3 8 25 55 836 3190 Shell 0 0 8 58 111 142
JavaScript
function swap(a, i, j){
var t = a[i]
a[i] = a[j]
a[j] = t
}
// Heap Sort
function heap_sort(a){
var n = a.length
function heapify(i){
var t = a[i]
while (true){
var l = 2 * i + 1, r = l + 1
var m = r < n ? (a[l] > a[r] ? l : r) : (l < n ? l : i)
if (m != i && a[m] > t){
a[i] = a[m]
i = m
}
else{
break
}
}
a[i] = t;
}
for (let i = Math.floor(n / 2) - 1; i >= 0; i--){
heapify(i)
}
for (let i = n - 1; i >= 1; i--){
swap(a, 0, i)
n--
heapify(0)
}
}
// Merge Sort
function merge_sort(a){
var b = new Array(a.length)
function rec(l, r){
if (l < r){
var m = Math.floor((l + r) / 2)
rec(l, m)
rec(m + 1, r)
var i = l, j = m + 1, k = 0;
while (i <= m && j <= r) b[k++] = (a[i] > a[j] ? a[j++] : a[i++])
while (j <= r) b[k++] = a[j++]
while (i <= m) b[k++] = a[i++]
for (k = l; k <= r; k++){
a[k] = b[k - l]
}
}
}
rec(0, a.length-1)
}
// Quick Sort
function quick_sort(a){
function rec(l, r){
if (l < r){
var p = a[l + Math.floor((r - l + 1)*Math.random())]
var i = l, j = l, k = r
while (j <= k){
if (a[j] < p){
swap(a, i++, j++)
}
else if (a[j] > p){
swap(a, j, k--)
}
else{
j++
}
}
rec(l, i - 1)
rec(k + 1, r)
}
}
rec(0, a.length - 1)
}
// Shell Sort
function shell_sort(a){
var n = a.length
var gaps = [100894, 44842, 19930, 8858, 3937, 1750, 701, 301, 132, 57, 23, 10, 4, 1]
for (let x of gaps){
for (let i = x; i < n; i++){
var t = a[i], j;
for (j = i; j >= x && a[j - x] > t; j -= x){
a[j] = a[j - x];
}
a[j] = t;
}
}
}
// Comb Sort (+ Insertion sort optimization)
function comb_sort(a){
var n = a.length
for (let x = n; x >= 10; x = Math.floor(x / 1.3)){
for (let i = 0; i + x < n; i++){
if (a[i] > a[i + x]){
swap(a, i, i + x)
}
}
}
for (let i = 1; i < n; i++){
var t = a[i], j;
for (j = i; j > 0 && a[j - 1] > t; j--){
a[j] = a[j - 1]
}
a[j] = t;
}
}
// Test
function test(f, g, e){
var res = ""
for (let n of e){
var a = new Array(n)
var s = 0
for (let k = 0; k < 10; k++){
for (let i = 0; i < n; i++){
a[i] = g(i)
}
var start = Date.now()
f(a)
s += Date.now() - start
}
res += Math.round(s / 10) + "\t"
}
return res
}
// Main
var e = [5000, 10000, 100000, 500000, 1000000, 2000000]
var sOut = "Test times in ms\n\nElements\t" + e.join("\t") + "\n\n"
sOut += "*All ones*\n"
sOut += "heap_sort\t" + test(heap_sort, (x => 1), e) + "\n"
sOut += "quick_sort\t" + test(quick_sort, (x => 1), e) + "\n"
sOut += "merge_sort\t" + test(merge_sort, (x => 1), e) + "\n"
sOut += "shell_sort\t" + test(shell_sort, (x => 1), e) + "\n"
sOut += "comb_sort\t" + test(comb_sort, (x => 1), e) + "\n\n"
sOut += "*Sorted*\n"
sOut += "heap_sort\t" + test(heap_sort, (x => x), e) + "\n"
sOut += "quick_sort\t" + test(quick_sort, (x => x), e) + "\n"
sOut += "merge_sort\t" + test(merge_sort, (x => x), e) + "\n"
sOut += "shell_sort\t" + test(shell_sort, (x => x), e) + "\n"
sOut += "comb_sort\t" + test(comb_sort, (x => x), e) + "\n\n"
sOut += "*Random*\n"
sOut += "heap_sort\t" + test(heap_sort, (x => Math.random()), e) + "\n"
sOut += "quick_sort\t" + test(quick_sort, (x => Math.random()), e) + "\n"
sOut += "merge_sort\t" + test(merge_sort, (x => Math.random()), e) + "\n"
sOut += "shell_sort\t" + test(shell_sort, (x => Math.random()), e) + "\n"
sOut += "comb_sort\t" + test(comb_sort, (x => Math.random()), e) + "\n"
console.log(sOut)
- Output:
Test times in ms Elements 5000 10000 100000 500000 1000000 2000000 *All ones* heap_sort 0 0 0 3 5 11 quick_sort 0 0 0 1 2 4 merge_sort 1 1 9 50 103 216 shell_sort 1 0 4 19 39 78 comb_sort 1 0 6 35 75 160 *Sorted* heap_sort 1 1 7 38 79 162 quick_sort 1 1 10 54 111 230 merge_sort 1 1 9 50 103 217 shell_sort 0 0 3 19 39 78 comb_sort 0 1 6 34 75 160 *Random* heap_sort 1 1 12 71 161 383 quick_sort 1 1 15 85 177 373 merge_sort 1 1 18 103 215 451 shell_sort 1 1 15 89 188 397 comb_sort 1 1 12 74 159 343
Julia
Julia comes with the InsertionSort, MergeSort, and QuickSort routines built into the Base.Sort module. Here is a comparison using those system algorithms and with integers.
function comparesorts(tosort)
a = shuffle(["i", "m", "q"])
iavg = mavg = qavg = 0.0
for c in a
if c == "i"
iavg = sum(i -> @elapsed(sort(tosort, alg=InsertionSort)), 1:100) / 100.0
elseif c == "m"
mavg = sum(i -> @elapsed(sort(tosort, alg=MergeSort)), 1:100) / 100.0
elseif c == "q"
qavg = sum(i -> @elapsed(sort(tosort, alg=QuickSort)), 1:100) / 100.0
end
end
iavg, mavg, qavg
end
allones = fill(1, 40000)
sequential = collect(1:40000)
randomized = collect(shuffle(1:40000))
comparesorts(allones)
comparesorts(allones)
iavg, mavg, qavg = comparesorts(allones)
println("Average sort times for 40000 ones:")
println("\tinsertion sort:\t$iavg\n\tmerge sort:\t$mavg\n\tquick sort\t$qavg")
comparesorts(sequential)
comparesorts(sequential)
iavg, mavg, qavg = comparesorts(sequential)
println("Average sort times for 40000 presorted:")
println("\tinsertion sort:\t$iavg\n\tmerge sort:\t$mavg\n\tquick sort\t$qavg")
comparesorts(randomized)
comparesorts(randomized)
iavg, mavg, qavg = comparesorts(randomized)
println("Average sort times for 40000 randomized:")
println("\tinsertion sort:\t$iavg\n\tmerge sort:\t$mavg\n\tquick sort\t$qavg")
Average sort times for 40000 ones: insertion sort: 0.00036058316000000005 merge sort: 0.00040099004999999996 quick sort 0.0003586394400000001 Average sort times for 40000 presorted: insertion sort: 0.0003141142199999999 merge sort: 0.0007967360000000003 quick sort 0.0005601127399999998 Average sort times for 40000 randomized: insertion sort: 0.2190664327599999 merge sort: 0.0028818907399999986 quick sort 0.0023325933899999997
Kotlin
This mostly reuses the code from the sorting sub-tasks except that:
1. All sorting functions have been adjusted where necessary so that they sort an IntArray 'in place'. This ensures that the timings are not affected by time spent copying arrays.
2. The bubble sort function, which is very slow when sorting 100,000 random numbers, has been optimized somewhat to try and reduce overall execution time, though the program is still taking about 5 minutes to run on my machine.
Unfortunately the code used to measure CPU time in the 'Time a function' sub-task no longer works properly on my present Windows 10 machine (many results are inexplicably zero). I've therefore had to use the Kotlin library function, measureNanoTime(), instead which measures system time elapsed. Consequently, the results are a bit erratic even when averaged over 10 runs.
Although it would be easy enough to plot the results graphically using an external library such as JFreePlot, there doesn't seem much point when we can no longer upload images to RC. I've therefore presented the results in tabular form on the terminal which is good enough to detect significant trends.
// Version 1.2.31
import java.util.Random
import kotlin.system.measureNanoTime
typealias Sorter = (IntArray) -> Unit
val rand = Random()
fun onesSeq(n: Int) = IntArray(n) { 1 }
fun ascendingSeq(n: Int) = shuffledSeq(n).sorted().toIntArray()
fun shuffledSeq(n: Int) = IntArray(n) { 1 + rand.nextInt(10 * n) }
fun bubbleSort(a: IntArray) {
var n = a.size
do {
var n2 = 0
for (i in 1 until n) {
if (a[i - 1] > a[i]) {
val tmp = a[i]
a[i] = a[i - 1]
a[i - 1] = tmp
n2 = i
}
}
n = n2
} while (n != 0)
}
fun insertionSort(a: IntArray) {
for (index in 1 until a.size) {
val value = a[index]
var subIndex = index - 1
while (subIndex >= 0 && a[subIndex] > value) {
a[subIndex + 1] = a[subIndex]
subIndex--
}
a[subIndex + 1] = value
}
}
fun quickSort(a: IntArray) {
fun sorter(first: Int, last: Int) {
if (last - first < 1) return
val pivot = a[first + (last - first) / 2]
var left = first
var right = last
while (left <= right) {
while (a[left] < pivot) left++
while (a[right] > pivot) right--
if (left <= right) {
val tmp = a[left]
a[left] = a[right]
a[right] = tmp
left++
right--
}
}
if (first < right) sorter(first, right)
if (left < last) sorter(left, last)
}
sorter(0, a.lastIndex)
}
fun radixSort(a: IntArray) {
val tmp = IntArray(a.size)
for (shift in 31 downTo 0) {
tmp.fill(0)
var j = 0
for (i in 0 until a.size) {
val move = (a[i] shl shift) >= 0
val toBeMoved = if (shift == 0) !move else move
if (toBeMoved)
tmp[j++] = a[i]
else {
a[i - j] = a[i]
}
}
for (i in j until tmp.size) tmp[i] = a[i - j]
for (i in 0 until a.size) a[i] = tmp[i]
}
}
val gaps = listOf(701, 301, 132, 57, 23, 10, 4, 1) // Marcin Ciura's gap sequence
fun shellSort(a: IntArray) {
for (gap in gaps) {
for (i in gap until a.size) {
val temp = a[i]
var j = i
while (j >= gap && a[j - gap] > temp) {
a[j] = a[j - gap]
j -= gap
}
a[j] = temp
}
}
}
fun main(args: Array<String>) {
val runs = 10
val lengths = listOf(1, 10, 100, 1_000, 10_000, 100_000)
val sorts = listOf<Sorter>(
::bubbleSort, ::insertionSort, ::quickSort, ::radixSort, ::shellSort
)
/* allow JVM to compile sort functions before timings start */
for (sort in sorts) sort(intArrayOf(1))
val sortTitles = listOf("Bubble", "Insert", "Quick ", "Radix ", "Shell ")
val seqTitles = listOf("All Ones", "Ascending", "Shuffled")
val totals = List(seqTitles.size) { List(sorts.size) { LongArray(lengths.size) } }
for ((k, n) in lengths.withIndex()) {
val seqs = listOf(onesSeq(n), ascendingSeq(n), shuffledSeq(n))
repeat(runs) {
for (i in 0 until seqs.size) {
for (j in 0 until sorts.size) {
val seq = seqs[i].copyOf()
totals[i][j][k] += measureNanoTime { sorts[j](seq) }
}
}
}
}
println("All timings in micro-seconds\n")
print("Sequence length")
for (len in lengths) print("%8d ".format(len))
println("\n")
for (i in 0 until seqTitles.size) {
println(" ${seqTitles[i]}:")
for (j in 0 until sorts.size) {
print(" ${sortTitles[j]} ")
for (k in 0 until lengths.size) {
val time = totals[i][j][k] / runs / 1_000
print("%8d ".format(time))
}
println()
}
println("\n")
}
}
- Output:
All timings in micro-seconds Sequence length 1 10 100 1000 10000 100000 All Ones: Bubble 1 2 6 24 26 264 Insert 1 16 10 14 48 518 Quick 2 7 18 46 397 5181 Radix 38 79 501 3720 864 9096 Shell 11 15 43 189 407 4105 Ascending: Bubble 1 2 6 8 24 270 Insert 0 2 9 14 47 496 Quick 1 6 19 33 282 3347 Radix 38 71 264 415 1869 21403 Shell 7 10 42 171 399 4052 Shuffled: Bubble 1 5 436 3292 275224 27730705 Insert 0 3 176 754 24759 2546180 Quick 1 7 24 106 1281 14982 Radix 28 73 622 317 1891 21617 Shell 11 19 88 408 1946 36980
Conclusions
As expected quick sort is faster than the other methods when applied to random data of a reasonable size though radix and shell sort are also respectable performers for large amounts of random data. In contrast, bubble and insertion sorts are orders of magnitude slower, particularly the former.
On the other hand, bubble and insertion sorts are much quicker than the other methods for constant data and for data which is already sorted in an ascending direction, bubble sort being the faster of the two.
Mathematica /Wolfram Language
Comparing bubble and shell sort:
ClearAll[BubbleSort,ShellSort]
BubbleSort[in_List]:=Module[{x=in,l=Length[in],swapped},swapped=True;
While[swapped,swapped=False;
Do[If[x[[i]]>x[[i+1]],x[[{i,i+1}]]//=Reverse;
swapped=True;],{i,l-1}];];
x]
ShellSort[lst_]:=Module[{list=lst,incr,temp,i,j},incr=Round[Length[list]/2];
While[incr>0,For[i=incr+1,i<=Length[list],i++,temp=list[[i]];j=i;
While[(j>=(incr+1))&&(list[[j-incr]]>temp),list[[j]]=list[[j-incr]];j=j-incr;];
list[[j]]=temp;];
If[incr==2,incr=1,incr=Round[incr/2.2]]];list
]
times=Table[
arr=ConstantArray[1,n];
t1={{n,AbsoluteTiming[BubbleSort[arr];][[1]]},{n,AbsoluteTiming[ShellSort[arr];][[1]]}};
arr=Sort[RandomInteger[{10^6},n]];
t2={{n,AbsoluteTiming[BubbleSort[arr];][[1]]},{n,AbsoluteTiming[ShellSort[arr];][[1]]}};
arr=RandomInteger[{10^6},n];
t3={{n,AbsoluteTiming[BubbleSort[arr];][[1]]},{n,AbsoluteTiming[ShellSort[arr];][[1]]}};
{t1,t2,t3}
,
{n,2^Range[13]}
];
ListLogLogPlot[Transpose@times[[All,1]],PlotLegends->{"Bubble","Shell"},PlotLabel->"Ones"]
ListLogLogPlot[Transpose@times[[All,2]],PlotLegends->{"Bubble","Shell"},PlotLabel->"Ascending integers"]
ListLogLogPlot[Transpose@times[[All,3]],PlotLegends->{"Bubble","Shell"},PlotLabel->"Shuffled"]
- Output:
Outputs three graphs on a log-log scales showing the size of the array and the time taken, for each of the three different arrays.
Nim
This is a direct translation of the Kotlin program. We have added the sorting algorithm provided by Nim standard library which is a merge sort. For this reason, we have been constrained to annotate the sorting functions with the pragma {.locks: "unknown".} to make their type compatible with that of the standard sort function.
We have also added the array as first parameter of the internal function “sorter” as Nim compiler doesn’t allow direct access to this mutable array in function “quicksort” (memory safety violation).
import algorithm
import random
import sequtils
import times
####################################################################################################
# Data.
proc oneSeq(n: int): seq[int] = repeat(1, n)
#---------------------------------------------------------------------------------------------------
proc shuffledSeq(n: int): seq[int] =
result.setLen(n)
for item in result.mitems: item = rand(1..(10 * n))
#---------------------------------------------------------------------------------------------------
proc ascendingSeq(n: int): seq[int] = sorted(shuffledSeq(n))
####################################################################################################
# Algorithms.
func bubbleSort(a: var openArray[int]) {.locks: "unknown".} =
var n = a.len
while true:
var n2 = 0
for i in 1..<n:
if a[i - 1] > a[i]:
swap a[i], a[i - 1]
n2 = i
n = n2
if n == 0: break
#---------------------------------------------------------------------------------------------------
func insertionSort(a: var openArray[int]) {.locks: "unknown".} =
for index in 1..a.high:
let value = a[index]
var subIndex = index - 1
while subIndex >= 0 and a[subIndex] > value:
a[subIndex + 1] = a[subIndex]
dec subIndex
a[subIndex + 1] = value
#---------------------------------------------------------------------------------------------------
func quickSort(a: var openArray[int]) {.locks: "unknown".} =
func sorter(a: var openArray[int]; first, last: int) =
if last - first < 1: return
let pivot = a[first + (last - first) div 2]
var left = first
var right = last
while left <= right:
while a[left] < pivot: inc left
while a[right] > pivot: dec right
if left <= right:
swap a[left], a[right]
inc left
dec right
if first < right: a.sorter(first, right)
if left < last: a.sorter(left, last)
a.sorter(0, a.high)
#---------------------------------------------------------------------------------------------------
func radixSort(a: var openArray[int]) {.locks: "unknown".} =
var tmp = newSeq[int](a.len)
for shift in countdown(63, 0):
for item in tmp.mitems: item = 0
var j = 0
for i in 0..a.high:
let move = a[i] shl shift >= 0
let toBeMoved = if shift == 0: not move else: move
if toBeMoved:
tmp[j] = a[i]
inc j
else:
a[i - j] = a[i]
for i in j..tmp.high: tmp[i] = a[i - j]
for i in 0..a.high: a[i] = tmp[i]
#---------------------------------------------------------------------------------------------------
func shellSort(a: var openArray[int]) {.locks: "unknown".} =
const Gaps = [701, 301, 132, 57, 23, 10, 4, 1]
for gap in Gaps:
for i in gap..a.high:
let temp = a[i]
var j = i
while j >= gap and a[j - gap] > temp:
a[j] = a[j - gap]
dec j, gap
a[j] = temp
#---------------------------------------------------------------------------------------------------
func standardSort(a: var openArray[int]) =
a.sort()
####################################################################################################
# Main code.
import strformat
const
Runs = 10
Lengths = [1, 10, 100, 1_000, 10_000, 100_000]
Sorts = [bubbleSort, insertionSort, quickSort, radixSort, shellSort, standardSort]
const
SortTitles = ["Bubble", "Insert", "Quick ", "Radix ", "Shell ", "Standard"]
SeqTitles = ["All Ones", "Ascending", "Shuffled"]
var totals: array[SeqTitles.len, array[Sorts.len, array[Lengths.len, Duration]]]
randomize()
for k, n in Lengths:
let seqs = [oneSeq(n), ascendingSeq(n), shuffledSeq(n)]
for _ in 1..Runs:
for i, s in seqs:
for j, sort in Sorts:
var s = s
let t0 = getTime()
s.sort()
totals[i][j][k] += getTime() - t0
echo "All timings in microseconds\n"
stdout.write "Sequence length "
for length in Lengths:
stdout.write &"{length:6d} "
echo '\n'
for i in 0..SeqTitles.high:
echo &" {SeqTitles[i]}:"
for j in 0..Sorts.high:
stdout.write &" {SortTitles[j]:8s} "
for k in 0..Lengths.high:
let time = totals[i][j][k].inMicroseconds div Runs
stdout.write &"{time:8d} "
echo ""
echo '\n'
- Output:
All timings in microseconds Sequence length 1 10 100 1000 10000 100000 All Ones: Bubble 0 0 0 0 6 64 Insert 0 0 0 1 9 90 Quick 0 0 3 9 105 1201 Radix 1 4 34 103 848 8354 Shell 0 0 2 10 97 946 Standard 0 2 2 6 45 380 Ascending: Bubble 0 0 0 0 6 61 Insert 0 0 0 1 9 94 Quick 0 0 3 11 88 919 Radix 1 5 47 154 1435 15519 Shell 0 0 2 10 95 954 Standard 0 0 2 7 47 463 Shuffled: Bubble 0 0 38 1026 133729 16181412 Insert 0 0 8 152 10010 1133210 Quick 0 0 9 63 607 7199 Radix 1 5 46 157 1405 15557 Shell 0 0 8 69 708 10236 Standard 0 0 18 96 992 12394
Conclusions
Compared to the results obtained by the Kotlin program, the radix sort seems less efficient and the shell sort more efficient. Maybe some optimizations could improve the radix sort, but it seems also that the shell sort is well optimized by the Nim compiler and the C compiler.
The standard sort behaves well if the list is already sorted. For random list, it is less efficient than the quick sort or the shell sort, but is still a good performer.
Perl
# 20241006 Perl programming solution
use strict;
use warnings;
use Time::HiRes qw(time);
my ($rounds, $size) = (3, 2000);
my @allones = (1) x $size;
my @sequential = (1 .. $size);
my @randomized = map { $sequential[rand @sequential] } 1 .. $size;
sub insertion_sort {
my @a = @_;
for my $k (1 .. $#a) {
my ($j, $value) = ($k - 1, $a[$k]);
while ($j >= 0 && $a[$j] > $value) {
$a[$j + 1] = $a[$j];
$j--;
}
$a[$j + 1] = $value;
}
return @a;
}
sub merge_sort {
my @a = @_;
return @a if @a <= 1;
my $m = int(@a / 2);
my @l = merge_sort(@a[0 .. $m - 1]);
my @r = merge_sort(@a[$m .. $#a]);
return (@l, @r) if $l[-1] <= $r[0];
my @result;
while (@l && @r) {
push @result, $l[0] <= $r[0] ? shift @l : shift @r;
}
push @result, @l, @r;
return @result;
}
sub quick_sort {
my @data = @_;
return @data if @data <= 1;
my $pivot_index = int(rand(@data));
my $pivot = $data[$pivot_index];
@data = grep { $_ != $pivot } @data;
my (@left, @right);
foreach my $x (@data) {
$x < $pivot ? push @left, $x : push @right, $x;
}
return (quick_sort(@left), $pivot, quick_sort(@right));
}
sub comparesorts {
my ($rounds, @tosort) = @_;
my ($iavg, $mavg, $qavg);
foreach my $sort_type (('i', 'm', 'q') x $rounds) {
my @data_copy = @tosort;
my $t = time;
if ($sort_type eq 'i') {
insertion_sort(@data_copy);
$iavg += time - $t;
} elsif ($sort_type eq 'm') {
merge_sort(@data_copy);
$mavg += time - $t;
} elsif ($sort_type eq 'q') {
quick_sort(@data_copy);
$qavg += time - $t;
}
}
return ($iavg / $rounds, $mavg / $rounds, $qavg / $rounds);
}
foreach my $test (['ones', @allones], ['presorted', @sequential], ['randomized', @randomized]) {
my ($t, @d) = @$test;
print "Average sort times for $size $t:\n";
my ($i_time, $m_time, $q_time) = comparesorts($rounds, @d);
printf "insertion sort %0.9f\n", $i_time;
printf "merge sort %0.9f\n", $m_time;
printf "quick sort %0.9f\n", $q_time;
}
You may Attempt This Online!
Phix
-- demo\rosetta\Compare_sorting_algorithms.exw constant XQS = 01 -- (set to 1 to exclude quick_sort and shell_sort from ones) include pGUI.e Ihandle dlg, tabs, plot Ihandles plots function quick_sort2(sequence x) integer n = length(x) if n<2 then return x -- already sorted (trivial case) end if integer mid = floor((n+1)/2), midn = 1 object midval = x[mid] sequence left = {}, right = {} x[mid] = x[1] for i=2 to n do object xi = x[i] integer c = compare(xi,midval) if c<0 then left = append(left,xi) elsif c>0 then right = append(right,xi) else midn += 1 end if end for return quick_sort2(left) & repeat(midval,midn) & quick_sort2(right) end function function quick_sort(sequence s) sequence qstack = repeat(0,floor((length(s)/5)+10)) -- create a stack integer first = 1, last = length(s), stackptr = 0 while true do while first<last do object pivot = s[floor(last+first)/2], si, sj integer I = first, J = last while true do while true do si = s[I] if si>=pivot then exit end if I += 1 end while while true do sj = s[J] if sj<=pivot then exit end if J -= 1 end while if I>J then exit end if if I<J then if si=sj then {I,J} = {J+1,I-1} exit end if s[I] = sj s[J] = si end if I += 1 J -= 1 if I>J then exit end if end while if I<last then qstack[stackptr+1] = I qstack[stackptr+2] = last stackptr += 2 end if last = J end while if stackptr=0 then exit end if stackptr -= 2 first = qstack[stackptr+1] last = qstack[stackptr+2] end while return s end function function radixSortn(sequence s, integer n) sequence buckets = repeat({},10) sequence res = {} for i=1 to length(s) do integer digit = remainder(floor(s[i]/power(10,n-1)),10)+1 buckets[digit] = append(buckets[digit],s[i]) end for for i=1 to length(buckets) do integer len = length(buckets[i]) if len!=0 then if len=1 or n=1 then res &= buckets[i] else res &= radixSortn(buckets[i],n-1) end if end if end for return res end function function split_by_sign(sequence s) sequence buckets = {{},{}} for i=1 to length(s) do integer si = s[i] if si<0 then buckets[1] = append(buckets[1],-si) else buckets[2] = append(buckets[2],si) end if end for return buckets end function function radix_sort(sequence s) -- NB this is an integer-only sort integer mins = min(s), passes = floor(log10(max(max(s),abs(mins))))+1 if mins<0 then sequence buckets = split_by_sign(s) buckets[1] = reverse(sq_uminus(radixSortn(buckets[1],passes))) buckets[2] = radixSortn(buckets[2],passes) s = buckets[1]&buckets[2] else s = radixSortn(s,passes) end if return s end function function shell_sort(sequence s) integer gap = floor(length(s)/2) while gap>0 do for i=gap to length(s) do object temp = s[i] integer j = i-gap while j>=1 and temp<=s[j] do s[j+gap] = s[j] j -= gap end while s[j+gap] = temp end for gap = floor(gap/2) end while return s end function function shell_sort2(sequence x) integer last = length(x), gap = floor(last/10)+1 while TRUE do integer first = gap+1 for i=first to last do object xi = x[i] integer j = i-gap while TRUE do object xj = x[j] if xi>=xj then j += gap exit end if x[j+gap] = xj if j<=gap then exit end if j -= gap end while x[j] = xi end for if gap=1 then return x else gap = floor(gap/3.5)+1 end if end while end function function siftDown(sequence arr, integer s, integer last) integer root = s while root*2<=last do integer child = root*2 if child<last and arr[child]<arr[child+1] then child += 1 end if if arr[root]>=arr[child] then exit end if object tmp = arr[root] arr[root] = arr[child] arr[child] = tmp root = child end while return arr end function function heapify(sequence arr, integer count) integer s = floor(count/2) while s>0 do arr = siftDown(arr,s,count) s -= 1 end while return arr end function function heap_sort(sequence arr) integer last = length(arr) arr = heapify(arr,last) while last>1 do object tmp = arr[1] arr[1] = arr[last] arr[last] = tmp last -= 1 arr = siftDown(arr,1,last) end while return arr end function include builtins/sort.e enum ONES = 1, SORTED = 2, RANDOM = 3, REVERSE = 4 constant tabtitles = {"ones","sorted","random","reverse"} integer tabidx = 3 integer STEP function tr(sequence name, integer rid=routine_id(name)) return {name,rid} end function constant tests = {tr("quick_sort"), tr("quick_sort2"), tr("radix_sort"), tr("shell_sort"), tr("shell_sort2"), tr("heap_sort"), tr("sort"), -- builtin } sequence results = repeat(repeat({}, length(tests)),length(tabtitles)) sequence dsdx = repeat(repeat(0,length(tests)),length(tabtitles)) integer ds_index function idle_action_cb() atom best = -1, -- fastest last besti = 0, -- 1..length(tests) bestt = 0, -- 1..length(tabtitles) len -- -- Search for something to do, active/visible tab first. -- Any result set of length 0 -> just do one. -- Of all result sets<8, pick the lowest [$]. -- sequence todo = {tabidx} for t=1 to length(tabtitles) do if t!=tabidx then todo &= t end if end for for t=1 to length(tabtitles) do integer ti = todo[t] for i=1 to length(results[ti]) do len = length(results[ti][i]) if len=0 then best = 0 besti = i bestt = ti exit elsif len<8 then if (best=-1) or (best>results[ti][i][$]) then best = results[ti][i][$] besti = i bestt = ti end if end if end for if (t=1) and (besti!=0) then exit end if end for if best>10 then -- cop out if it is getting too slow besti = 0 end if if besti!=0 then STEP = iff(not XQS and bestt=ONES?1000:100000) len = (length(results[bestt][besti])+1)*STEP sequence test = iff(bestt=ONES?repeat(1,len): iff(bestt=SORTED?tagset(len): iff(bestt=RANDOM?shuffle(tagset(len)): iff(bestt=REVERSE?reverse(tagset(len)):9/0)))) ds_index = dsdx[bestt][besti] atom t0 = time() sequence check = call_func(tests[besti][2],{test}) t0 = time()-t0 -- if check!=sort(test) then ?9/0 end if plot = plots[bestt] IupPlotInsert(plot, ds_index, -1, len, t0) results[bestt][besti] = append(results[bestt][besti],t0) IupSetAttribute(plot,"REDRAW",NULL) sequence progress = {bestt} for i=1 to length(results[bestt]) do progress &= length(results[bestt][i]) end for IupSetStrAttribute(dlg,"TITLE","Compare sorting algorithms %s",{sprint(progress)}) return IUP_CONTINUE end if IupSetAttribute(dlg,"TITLE","Compare sorting algorithms (all done, idle)") return IUP_IGNORE -- all done, remove callback end function constant cb_idle_action = Icallback("idle_action_cb") function tabchange_cb(Ihandle /*self*/, Ihandle /*new_tab*/) tabidx = IupGetInt(tabs,"VALUEPOS")+1 plot = plots[tabidx] return IUP_DEFAULT; end function procedure main() IupOpen() plots = {} for i=1 to length(tabtitles) do if XQS then -- results[ONES][1] = repeat(0,8) results[ONES][4] = repeat(0,8) end if plot = IupPlot() IupSetAttribute(plot,"MENUITEMPROPERTIES","YES") IupSetAttribute(plot,"TABTITLE",tabtitles[i]) IupSetAttribute(plot,"GRID","YES") IupSetAttribute(plot,"MARGINLEFT","50") IupSetAttribute(plot,"MARGINBOTTOM","40") IupSetAttribute(plot,"LEGEND","YES") IupSetAttribute(plot,"LEGENDPOS","TOPLEFT") -- IupSetAttribute(plot,"AXS_YSCALE","LOG10") -- IupSetAttribute(plot,"AXS_XSCALE","LOG10") for j=1 to length(tests) do IupPlotBegin(plot) dsdx[i][j] = IupPlotEnd(plot) IupSetAttribute(plot,"DS_NAME",tests[j][1]) end for plots = append(plots,plot) end for tabs = IupTabs(plots) IupSetCallback(tabs, "TABCHANGE_CB", Icallback("tabchange_cb")) dlg = IupDialog(tabs, "RASTERSIZE=800x480") IupSetAttribute(dlg, "TITLE", "Compare sorting algorithms") IupShow(dlg) IupSetInt(tabs, "VALUEPOS", tabidx-1) IupSetGlobalFunction("IDLE_ACTION", cb_idle_action) if platform()!=JS then IupMainLoop() IupClose() end if end procedure main()
Conclusions
I knew bubblesort and insertion sort would be bad, but not so bad that you cannot meaningfully plot them against better sorts. (logarithmic scale helps, but is still not enough) I had no idea that (these particular implementations of) quicksort and shellsort would be so bad on a sequence of all 1s. (so bad in fact that I had to cap that test length to 8,000 instead of 800,000 as used for the other tests) The builtin sort and shell_sort2 were the clear winners, until I found a non-recursive quicksort that seems quite good. IupPlot is brilliant! It is actually quite fun to watch the graphs grow as you get more results in! There is a point where you realise you are currently wasting your life fretting over 0.015 seconds...
The ultimate conclusion is, of course, that there are some differences, but as long as you weed out the really bad algorithms, and at least in the majority of cases, you will probably never notice whether sorting 800,000 items takes 0.25s or 0.1s - more significant gains are likely to be found elsewhere.
Python
Examples of sorting routines
def builtinsort(x):
x.sort()
def partition(seq, pivot):
low, middle, up = [], [], []
for x in seq:
if x < pivot:
low.append(x)
elif x == pivot:
middle.append(x)
else:
up.append(x)
return low, middle, up
import random
def qsortranpart(seq):
size = len(seq)
if size < 2: return seq
low, middle, up = partition(seq, random.choice(seq))
return qsortranpart(low) + middle + qsortranpart(up)
Sequence generators
def ones(n):
return [1]*n
def reversedrange(n):
return reversed(range(n))
def shuffledrange(n):
x = range(n)
random.shuffle(x)
return x
Write timings
def write_timings(npoints=10, maxN=10**4, sort_functions=(builtinsort,insertion_sort, qsort),
sequence_creators = (ones, range, shuffledrange)):
Ns = range(2, maxN, maxN//npoints)
for sort in sort_functions:
for make_seq in sequence_creators:
Ts = [usec(sort, (make_seq(n),)) for n in Ns]
writedat('%s-%s-%d-%d.xy' % (sort.__name__, make_seq.__name__, len(Ns), max(Ns)), Ns, Ts)
Where writedat() is defined in the Write float arrays to a text file, usec() - Query Performance, insertion_sort() - Insertion sort, qsort - Quicksort subtasks, correspondingly.
Plot timings
import operator
import numpy, pylab
def plotdd(dictplotdict):
"""See ``plot_timings()`` below."""
symbols = ('o', '^', 'v', '<', '>', 's', '+', 'x', 'D', 'd',
'1', '2', '3', '4', 'h', 'H', 'p', '|', '_')
colors = list('bgrcmyk') # split string on distinct characters
for npoints, plotdict in dictplotdict.iteritems():
for ttle, lst in plotdict.iteritems():
pylab.hold(False)
for i, (label, polynom, x, y) in enumerate(sorted(lst,key=operator.itemgetter(0))):
pylab.plot(x, y, colors[i % len(colors)] + symbols[i % len(symbols)], label='%s %s' % (polynom, label))
pylab.hold(True)
y = numpy.polyval(polynom, x)
pylab.plot(x, y, colors[i % len(colors)], label= '_nolegend_')
pylab.legend(loc='upper left')
pylab.xlabel(polynom.variable)
pylab.ylabel('log2( time in microseconds )')
pylab.title(ttle, verticalalignment='bottom')
figname = '_%(npoints)03d%(ttle)s' % vars()
pylab.savefig(figname+'.png')
pylab.savefig(figname+'.pdf')
print figname
See Plot x, y arrays and Polynomial Fitting subtasks for a basic usage of pylab.plot() and numpy.polyfit().
import collections, itertools, glob, re
import numpy
def plot_timings():
makedict = lambda: collections.defaultdict(lambda: collections.defaultdict(list))
df = makedict()
ds = makedict()
# populate plot dictionaries
for filename in glob.glob('*.xy'):
m = re.match(r'([^-]+)-([^-]+)-(\d+)-(\d+)\.xy', filename)
print filename
assert m, filename
funcname, seqname, npoints, maxN = m.groups()
npoints, maxN = int(npoints), int(maxN)
a = numpy.fromiter(itertools.imap(float, open(filename).read().split()), dtype='f')
Ns = a[::2] # sequences lengths
Ts = a[1::2] # corresponding times
assert len(Ns) == len(Ts) == npoints
assert max(Ns) <= maxN
#
logsafe = numpy.logical_and(Ns>0, Ts>0)
Ts = numpy.log2(Ts[logsafe])
Ns = numpy.log2(Ns[logsafe])
coeffs = numpy.polyfit(Ns, Ts, deg=1)
poly = numpy.poly1d(coeffs, variable='log2(N)')
#
df[npoints][funcname].append((seqname, poly, Ns, Ts))
ds[npoints][seqname].append((funcname, poly, Ns, Ts))
# actual plotting
plotdd(df)
plotdd(ds) # see ``plotdd()`` above
Figures: log2( time in microseconds ) vs. log2( sequence length )
sort_functions = [
builtinsort, # see implementation above
insertion_sort, # see [[Insertion sort]]
insertion_sort_lowb, # ''insertion_sort'', where sequential search is replaced
# by lower_bound() function
qsort, # see [[Quicksort]]
qsortranlc, # ''qsort'' with randomly choosen ''pivot''
# and the filtering via list comprehension
qsortranpart, # ''qsortranlc'' with filtering via ''partition'' function
qsortranpartis, # ''qsortranpart'', where for a small input sequence lengths
] # ''insertion_sort'' is called
if __name__=="__main__":
import sys
sys.setrecursionlimit(10000)
write_timings(npoints=100, maxN=1024, # 1 <= N <= 2**10 an input sequence length
sort_functions=sort_functions,
sequence_creators = (ones, range, shuffledrange))
plot_timings()
Executing above script we get belowed figures.
ones
ones.png (143KiB)
builtinsort - O(N) insertion_sort - O(N) qsort - O(N**2) qsortranpart - O(N)
range
range.png (145KiB)
builtinsort - O(N) insertion_sort - O(N) qsort - O(N**2) qsortranpart - O(N*log(N))
shuffled range
shuffledrange.png (152KiB)
builtinsort - O(N) insertion_sort - O(N**4) ??? qsort - O(N*log(N)) qsortranpart - O(N) ???
Raku
# 20221114 Raku programming solution
my ($rounds,$size) = 3, 2000;
my @allones = 1 xx $size;
my @sequential = 1 .. $size;
my @randomized = @sequential.roll xx $size;
sub insertion_sort ( @a is copy ) { # rosettacode.org/wiki/Sorting_algorithms/Insertion_sort#Raku
for 1 .. @a.end -> \k {
loop (my ($j,\value)=k-1,@a[k];$j>-1&&@a[$j]>value;$j--) {@a[$j+1]=@a[$j]}
@a[$j+1] = value;
}
return @a;
}
sub merge_sort ( @a ) { # rosettacode.org/wiki/Sorting_algorithms/Merge_sort#Raku
return @a if @a <= 1;
my $m = @a.elems div 2;
my @l = merge_sort @a[ 0 ..^ $m ];
my @r = merge_sort @a[ $m ..^ @a ];
return flat @l, @r if @l[*-1] !after @r[0];
return flat gather {
take @l[0] before @r[0] ?? @l.shift !! @r.shift
while @l and @r;
take @l, @r;
}
}
sub quick-sort(@data) { # andrewshitov.com/2019/06/23/101-quick-sort-in-perl-6/
return @data if @data.elems <= 1;
my ($pivot,@left, @right) = @data[0];
for @data[1..*] -> $x { $x < $pivot ?? push @left, $x !! push @right, $x }
return flat(quick-sort(@left), $pivot, quick-sort(@right));
}
sub comparesorts($rounds, @tosort) {
my ( $iavg, $mavg, $qavg, $t );
for (<i m q> xx $rounds).flat.pick(*) -> \sort_type {
given sort_type {
when 'i' { $t = now ; insertion_sort @tosort ; $iavg += now - $t }
when 'm' { $t = now ; merge_sort @tosort ; $mavg += now - $t }
when 'q' { $t = now ; quick-sort @tosort ; $qavg += now - $t }
}
}
return $iavg, $mavg, $qavg »/» $rounds
}
for <ones presorted randomized>Z(@allones,@sequential,@randomized) -> ($t,@d) {
say "Average sort times for $size $t:";
{ say "\tinsertion sort\t$_[0]\n\tmerge sort\t$_[1]\n\tquick sort\t$_[2]" }(comparesorts $rounds,@d)
}
- Output:
Average sort times for 2000 ones: insertion sort 0.112333083 merge sort 0.506624066 quick sort 5.899009606666667 Average sort times for 2000 presorted: insertion sort 0.03596163 merge sort 0.474839352 quick sort 5.896118350666666 Average sort times for 2000 randomized: insertion sort 5.352926729 merge sort 0.784896982 quick sort 0.11422247299999999
REXX
One goal for this REXX program was to include as many different sorts (that sorted arrays and not lists).
Because of the disparencies of some sorting algorithms, the range of numbers was chosen to be 5 so that the
slower sorts wouldn't consume a lot of time trying to sort larger arrays.
The number of ranges can be increased at the expense of a wider display of output.
/*REXX pgm compares various sorts for 3 types of input sequences: ones/ascending/random.*/
parse arg ranges start# seed . /*obtain optional arguments from the CL*/
if ranges=='' | ranges=="," then ranges= 5 /*Not Specified? Then use the default.*/
if start#=='' | start#=="," then start#= 250 /* " " " " " " */
if seed=='' | seed=="," then seed= 1946 /*use a repeatable seed for RANDOM BIF*/
if datatype(seed, 'W') then call random ,,seed /*Specified? Then use as a RANDOM seed*/
kinds= 3; hdr=; #= start# /*hardcoded/fixed number of datum kinds*/
do ra=1 for ranges
hdr= hdr || center( commas(#) "numbers", 25)'│' /*(top) header for the output title.*/
do ki=1 for kinds
call gen@@ #, ki
call set@; call time 'R'; call bubble #; bubble.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call cocktail #; cocktail.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call cocktailSB #; cocktailSB.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call comb #; comb.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call exchange #; exchange.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call gnome #; gnome.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call heap #; heap.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call insertion #; insertion.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call merge #; merge.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call pancake #; pancake.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call quick #; quick.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call radix #; radix.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call selection #; selection.ra.ki= format(time("E"),,2)
call set@; call time 'R'; call shell #; shell.ra.ki= format(time("E"),,2)
end /*ki*/
#= # + # /*double # elements.*/
end /*ra*/
say; say; say /*say blank sep line*/
say center(' ', 11 ) "│"left(hdr, length(hdr)-1)"│" /*replace last char.*/
reps= ' allONES ascend random │' /*build a title bar.*/
xreps= copies( center(reps, length(reps)), ranges) /*replicate ranges. */
creps= left(xreps, length(xreps)-1)"│" /*replace last char.*/
say center('sort type', 11 ) "│"creps; Lr= length(reps)
xcreps= copies( left('', Lr-1, '─')"┼", ranges)
say center('' , 12, '─')"┼"left(xcreps, length(xcreps)-1)"┤"
call show 'bubble' /* ◄──── show results for bubble sort.*/
call show 'cocktail' /* ◄──── " " " cocktail " */
call show 'cocktailSB' /*+Shifting Bounds*/ /* ◄──── " " " cocktailSB " */
call show 'comb' /* ◄──── " " " comb " */
call show 'exchange' /* ◄──── " " " exchange " */
call show 'gnome' /* ◄──── " " " gnome " */
call show 'heap' /* ◄──── " " " heap " */
call show 'insertion' /* ◄──── " " " insertion " */
call show 'merge' /* ◄──── " " " merge " */
call show 'pancake' /* ◄──── " " " pancake " */
call show 'quick' /* ◄──── " " " quick " */
call show 'radix' /* ◄──── " " " radix " */
call show 'selection' /* ◄──── " " " shell " */
call show 'shell' /* ◄──── " " " shell " */
say translate(center('' , 12, '─')"┴"left(xcreps, length(xcreps)-1)"┘", '┴', "┼")
exit 0 /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
commas: parse arg ?; do jc=length(?)-3 to 1 by -3; ?=insert(',', ?, jc); end; return ?
inOrder: parse arg n; do j=1 for n-1; k= j+1; if @.j>@.k then return 0; end; return 1
set@: @.=; do a=1 for #; @.a= @@.a; end; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
gen@@: procedure expose @@.; parse arg n,kind; nn= min(n, 100000) /*1e5≡REXX's max.*/
do j=1 for nn; select
when kind==1 then @@.j= 1 /*all ones. */
when kind==2 then @@.j= j /*ascending.*/
when kind==3 then @@.j= random(, nn) /*random. */
end /*select*/
end /*j*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
show: parse arg aa; _= left(aa, 11) "│"
do ra=1 for ranges
do ki=1 for kinds
_= _ right( value(aa || . || ra || . || ki), 7, ' ')
end /*k*/
_= _ "│"
end /*r*/; say _; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
bubble: procedure expose @.; parse arg n /*N: is the number of @ elements. */
do m=n-1 by -1 until ok; ok=1 /*keep sorting @ array until done.*/
do j=1 for m; k=j+1; if @.j<=@.k then iterate /*elements in order? */
_=@.j; @.j=@.k; @.k=_; ok=0 /*swap 2 elements; flag as not done.*/
end /*j*/
end /*m*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
cocktail: procedure expose @.; parse arg N; nn= N-1 /*N: is number of items. */
do until done; done= 1
do j=1 for nn; jp= j+1
if @.j>@.jp then do; done=0; _=@.j; @.j=@.jp; @.jp=_; end
end /*j*/
if done then leave /*No swaps done? Finished.*/
do k=nn for nn by -1; kp= k+1
if @.k>@.kp then do; done=0; _=@.k; @.k=@.kp; @.kp=_; end
end /*k*/
end /*until*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
cocktailsb: procedure expose @.; parse arg N /*N: is number of items. */
end$= N - 1; beg$= 1
do while beg$ <= end$
beg$$= end$; end$$= beg$
do j=beg$ to end$; jp= j + 1
if @.j>@.jp then do; _=@.j; @.j=@.jp; @.jp=_; end$$=j; end
end /*j*/
end$= end$$ - 1
do k=end$ to beg$ by -1; kp= k + 1
if @.k>@.kp then do; _=@.k; @.k=@.kp; @.kp=_; beg$$=k; end
end /*k*/
beg$= beg$$ + 1
end /*while*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
comb: procedure expose @.; parse arg n /*N: is the number of @ elements. */
g= n-1 /*G: is the gap between the sort COMBs*/
do until g<=1 & done; done= 1 /*assume sort is done (so far). */
g= g * 0.8 % 1 /*equivalent to: g= trunc( g / 1.25) */
if g==0 then g= 1 /*handle case of the gap is too small. */
do j=1 until $>=n; $= j + g /*$: a temporary index (pointer). */
if @.j>@.$ then do; _= @.j; @.j= @.$; @.$= _; done= 0; end
end /*j*/ /* [↑] swap two elements in the array.*/
end /*until*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
exchange: procedure expose @.; parse arg n 1 h /*both N and H have the array size.*/
do while h>1; h= h % 2
do i=1 for n-h; j= i; k= h+i
do while @.k<@.j
_= @.j; @.j= @.k; @.k= _; if h>=j then leave; j= j-h; k= k-h
end /*while @.k<@.j*/
end /*i*/
end /*while h>1*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
gnome: procedure expose @.; parse arg n; k= 2 /*N: is number items. */
do j=3 while k<=n; p= k - 1 /*P: is previous item.*/
if @.p<<=@.k then do; k= j; iterate; end /*order is OK so far. */
_= @.p; @.p= @.k; @.k= _ /*swap two @ entries. */
k= k - 1; if k==1 then k= j; else j= j-1 /*test for 1st index. */
end /*j*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
heap: procedure expose @.; arg n; do j=n%2 by -1 to 1; call heapS j,n; end /*j*/
do n=n by -1 to 2; _= @.1; @.1= @.n; @.n= _; call heapS 1,n-1
end /*n*/; return /* [↑] swap two elements; and shuffle.*/
heapS: procedure expose @.; parse arg i,n; $= @.i /*obtain parent.*/
do while i+i<=n; j= i+i; k= j+1; if k<=n then if @.k>@.j then j= k
if $>=@.j then leave; @.i= @.j; i= j
end /*while*/; @.i= $; return /*define lowest.*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
insertion: procedure expose @.; parse arg n
do i=2 to n; $= @.i; do j=i-1 by -1 to 1 while @.j>$
_= j + 1; @._= @.j
end /*j*/
_= j + 1; @._= $
end /*i*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
merge: procedure expose @. !.; parse arg n, L; if L=='' then do; !.=; L= 1; end
if n==1 then return; h= L + 1
if n==2 then do; if @.L>@.h then do; _=@.h; @.h=@.L; @.L=_; end; return; end
m= n % 2 /* [↑] handle case of two items.*/
call merge n-m, L+m /*divide items to the left ···*/
call merger m, L, 1 /* " " " " right ···*/
i= 1; j= L + m
do k=L while k<j /*whilst items on right exist ···*/
if j==L+n | !.i<=@.j then do; @.k= !.i; i= i + 1; end
else do; @.k= @.j; j= j + 1; end
end /*k*/; return
merger: procedure expose @. !.; parse arg n,L,T
if n==1 then do; !.T= @.L; return; end
if n==2 then do; h= L + 1; q= T + 1; !.q= @.L; !.T= @.h; return; end
m= n % 2 /* [↑] handle case of two items.*/
call merge m, L /*divide items to the left ···*/
call merger n-m, L+m, m+T /* " " " " right ···*/
i= L; j= m + T
do k=T while k<j /*whilst items on left exist ···*/
if j==T+n | @.i<=!.j then do; !.k= @.i; i= i + 1; end
else do; !.k= !.j; j= j + 1; end
end /*k*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
pancake: procedure expose @.; parse arg n .; if inOrder(n) then return
do n=n by -1 for n-1
!= @.1; ?= 1; do j=2 to n; if @.j<=! then iterate
!= @.j; ?= j
end /*j*/
call panFlip ?; call panFlip n
end /*n*/; return
panFlip: parse arg y; do i=1 for (y+1)%2; yi=y-i+1; _=@.i; @.i=@.yi; @.yi=_; end; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
quick: procedure expose @.; a.1=1; parse arg b.1; $= 1 /*access @.; get #; define pivot.*/
if inOrder(b.1) then return
do while $\==0; L= a.$; t= b.$; $= $-1; if t<2 then iterate
H= L+t-1; ?= L+t%2
if @.H<@.L then if @.?<@.H then do; p=@.H; @.H=@.L; end
else if @.?>@.L then p=@.L
else do; p=@.?; @.?=@.L; end
else if @.?<@.L then p=@.L
else if @.?>@.H then do; p=@.H; @.H=@.L; end
else do; p=@.?; @.?=@.L; end
j= L+1; k=h
do forever
do j=j while j<k & @.j<=p; end /*a tinie─tiny loop.*/
do k=k by -1 while j<k & @.k>=p; end /*another " " */
if j>=k then leave /*segment finished? */
_= @.j; @.j= @.k; @.k= _ /*swap J&K elements.*/
end /*forever*/
$= $+1; k= j-1; @.L= @.k; @.k= p
if j<=? then do; a.$= j; b.$= H-j+1; $= $+1; a.$= L; b.$= k-L; end
else do; a.$= L; b.$= k-L; $= $+1; a.$= j; b.$= H-j+1; end
end /*while $¬==0*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
radix: procedure expose @.; parse arg size,w; mote= c2d(' '); #= 1; !.#._n= size
!.#._b= 1; if w=='' then w= 8
!.#._i= 1; do i=1 for size; y=@.i; @.i= right(abs(y), w, 0); if y<0 then @.i= '-'@.i
end /*i*/ /* [↑] negative case.*/
do while #\==0; ctr.= 0; L= 'ffff'x; low= !.#._b; n= !.#._n; $= !.#._i; H=
#= #-1 /* [↑] is the radix. */
do j=low for n; parse var @.j =($) _ +1; ctr._= ctr._ + 1
if ctr._==1 & _\=='' then do; if _<<L then L=_; if _>>H then H=_
end /* ↑↑ */
end /*j*/ /* └┴─────◄─── << is a strict comparison.*/
_= /* ┌──◄─── >> " " " " */
if L>>H then iterate /*◄─────┘ */
if L==H & ctr._==0 then do; #= #+1; !.#._b= low; !.#._n= n; !.#._i= $+1; iterate
end
L= c2d(L); H= c2d(H); ?= ctr._ + low; top._= ?; ts= mote
max= L
do k=L to H; _= d2c(k, 1); c= ctr._ /* [↓] swap 2 item radices.*/
if c>ts then parse value c k with ts max; ?= ?+c; top._= ?
end /*k*/
piv= low /*set PIVot to the low part of the sort*/
do while piv<low+n
it= @.piv
do forever; parse var it =($) _ +1; c= top._ -1
if piv>=c then leave; top._= c; ?= @.c; @.c= it; it= ?
end /*forever*/
top._= piv; @.piv= it; piv= piv + ctr._
end /*while piv<low+n */
i= max
do until i==max; _= d2c(i, 1); i= i+1; if i>H then i= L; d= ctr._
if d<=mote then do; if d<2 then iterate; b= top._
do k=b+1 for d-1; q= @.k
do j=k-1 by -1 to b while q<<@.j; jp= j+1; @.jp= @.j
end /*j*/
jp= j+1; @.jp= q
end /*k*/
iterate
end
#= #+1; !.#._b= top._; !.#._n= d; !.#._i= $ + 1
end /*until i==max*/
end /*while #\==0 */
#= 0 /* [↓↓↓] handle neg. and pos. arrays. */
do i=size by -1 for size; if @.i>=0 then iterate; #= #+1; @@.#= @.i
end /*i*/
do j=1 for size; if @.j>=0 then do; #= #+1; @@.#= @.j; end; @.j= @@.j+0
end /*j*/ /* [↑↑↑] combine 2 lists into 1 list. */
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
selection: procedure expose @.; parse arg n
do j=1 for n-1; _= @.j; p= j
do k=j+1 to n; if @.k>=_ then iterate
_= @.k; p= k /*this item is out─of─order, swap later*/
end /*k*/
if p==j then iterate /*if the same, the order of items is OK*/
_= @.j; @.j= @.p; @.p= /*swap 2 items that're out─of─sequence.*/
end /*j*/; return
/*──────────────────────────────────────────────────────────────────────────────────────*/
shell: procedure expose @.; parse arg N /*obtain the N from the argument list*/
i= N % 2 /*% is integer division in REXX. */
do while i\==0
do j=i+1 to N; k= j; p= k-i /*P: previous item*/
_= @.j
do while k>=i+1 & @.p>_; @.k= @.p; k= k-i; p= k-i
end /*while k≥i+1*/
@.k= _
end /*j*/
if i==2 then i= 1
else i= i * 5 % 11
end /*while i¬==0*/; return
- output when using the default inputs:
(Shown at 7/8 size.)
| 500 numbers | 1,000 numbers | 2,000 numbers | 4,000 numbers | 8,000 numbers | sort type | allONES ascend random | allONES ascend random | allONES ascend random | allONES ascend random | allONES ascend random | ------------+-------------------------+-------------------------+-------------------------+-------------------------+-------------------------| bubble | 0.00 0.00 0.05 | 0.00 0.00 0.18 | 0.00 0.00 0.75 | 0.00 0.00 2.96 | 0.00 0.00 12.40 | cocktail | 0.00 0.00 0.05 | 0.00 0.00 0.18 | 0.00 0.00 0.78 | 0.00 0.00 3.03 | 0.00 0.00 12.60 | cocktailSB | 0.00 0.00 0.04 | 0.00 0.00 0.15 | 0.00 0.00 0.63 | 0.00 0.00 2.48 | 0.00 0.00 10.31 | comb | 0.00 0.00 0.00 | 0.01 0.01 0.01 | 0.01 0.01 0.02 | 0.03 0.03 0.04 | 0.07 0.07 0.08 | exchange | 0.00 0.00 0.00 | 0.00 0.00 0.01 | 0.00 0.00 0.02 | 0.01 0.01 0.04 | 0.02 0.02 0.10 | gnome | 0.00 0.02 0.04 | 0.00 0.03 0.15 | 0.00 0.66 0.64 | 0.00 1.72 2.66 | 0.00 3.01 10.58 | heap | 0.00 0.00 0.00 | 0.00 0.01 0.01 | 0.01 0.02 0.02 | 0.01 0.04 0.04 | 0.02 0.09 0.09 | insertion | 0.00 0.00 0.02 | 0.00 0.00 0.08 | 0.00 0.00 0.32 | 0.00 0.00 1.32 | 0.00 0.00 5.28 | merge | 0.00 0.00 0.00 | 0.00 0.00 0.01 | 0.01 0.01 0.01 | 0.02 0.02 0.03 | 0.04 0.04 0.06 | pancake | 0.00 0.00 0.05 | 0.00 0.00 0.20 | 0.00 0.00 0.84 | 0.00 0.00 3.44 | 0.00 0.00 13.71 | quick | 0.00 0.00 0.00 | 0.00 0.00 0.00 | 0.00 0.00 0.01 | 0.00 0.00 0.02 | 0.00 0.00 0.04 | radix | 0.00 0.00 0.00 | 0.00 0.01 0.01 | 0.01 0.01 0.01 | 0.02 0.02 0.02 | 0.03 0.05 0.05 | selection | 0.02 0.01 0.02 | 0.05 0.05 0.06 | 0.21 0.22 0.27 | 0.85 0.83 0.94 | 3.63 3.47 4.22 | shell | 0.00 0.00 0.00 | 0.00 0.00 0.01 | 0.01 0.01 0.02 | 0.02 0.02 0.04 | 0.04 0.04 0.09 | ----------------------------------------------------------------------------------------------------------------------------------------------- | 16,000 numbers | 32,000 numbers | 64,000 numbers | 128,000 numbers | 256,000 numbers | sort type | allONES ascend random | allONES ascend random | allONES ascend random | allONES ascend random | allONES ascend random | ------------+-------------------------+-------------------------+-------------------------+-------------------------+-------------------------| comb | 0.13 0.13 0.19 | 0.29 0.30 0.40 | 0.63 0.65 0.89 | 1.59 1.63 2.12 | 4.13 4.51 5.35 | exchange | 0.05 0.05 0.24 | 0.11 0.11 0.65 | 0.23 0.23 1.60 | 0.54 0.59 3.25 | 1.49 1.58 4.69 | heap | 0.04 0.19 0.19 | 0.09 0.41 0.42 | 0.19 0.89 0.92 | 0.78 1.99 2.22 | 3.57 4.73 5.25 | merge | 0.08 0.08 0.14 | 0.17 0.17 0.30 | 0.35 0.36 0.70 | 0.82 0.85 1.32 | 1.97 2.01 2.53 | quick | 0.00 0.00 0.10 | 0.01 0.01 0.18 | 0.02 0.02 0.44 | 0.04 0.04 0.83 | 0.10 0.09 1.69 | shell | 0.09 0.10 0.20 | 0.21 0.22 0.42 | 0.46 0.47 0.94 | 1.04 1.09 1.90 | 2.61 2.41 3.53 | ----------------------------------------------------------------------------------------------------------------------------------------------- (given code for Radix sort failed for N > 10000, therefore the same is excluded from second list) All timings for Regina, Windows 11, Intel i7 4.5GHz, 16GB.
Ruby
class Array
def radix_sort(base=10) # negative value is inapplicable.
ary = dup
rounds = (Math.log(ary.max)/Math.log(base)).ceil
rounds.times do |i|
buckets = Array.new(base){[]}
base_i = base**i
ary.each do |n|
digit = (n/base_i) % base
buckets[digit] << n
end
ary = buckets.flatten
end
ary
end
def quick_sort
return self if size <= 1
pivot = sample
g = group_by{|x| x<=>pivot}
g.default = []
g[-1].quick_sort + g[0] + g[1].quick_sort
end
def shell_sort
inc = size / 2
while inc > 0
(inc...size).each do |i|
value = self[i]
while i >= inc and self[i - inc] > value
self[i] = self[i - inc]
i -= inc
end
self[i] = value
end
inc = (inc == 2 ? 1 : (inc * 5.0 / 11).to_i)
end
self
end
def insertion_sort
(1...size).each do |i|
value = self[i]
j = i - 1
while j >= 0 and self[j] > value
self[j+1] = self[j]
j -= 1
end
self[j+1] = value
end
self
end
def bubble_sort
(1...size).each do |i|
(0...size-i).each do |j|
self[j], self[j+1] = self[j+1], self[j] if self[j] > self[j+1]
end
end
self
end
end
data_size = [1000, 10000, 100000, 1000000]
data = []
data_size.each do |size|
ary = *1..size
data << [ [1]*size, ary, ary.shuffle, ary.reverse ]
end
data = data.transpose
data_type = ["set to all ones", "ascending sequence", "randomly shuffled", "descending sequence"]
print "Array size: "
puts data_size.map{|size| "%9d" % size}.join
data.each_with_index do |arys,i|
puts "\nData #{data_type[i]}:"
[:sort, :radix_sort, :quick_sort, :shell_sort, :insertion_sort, :bubble_sort].each do |m|
printf "%20s ", m
flag = true
arys.each do |ary|
if flag
t0 = Time.now
ary.dup.send(m)
printf " %7.3f", (t1 = Time.now - t0)
flag = false if t1 > 2
else
print " --.---"
end
end
puts
end
end
Array#sort is a built-in method.
- Output:
Array size: 1000 10000 100000 1000000 Data set to all ones: sort 0.000 0.001 0.005 0.043 radix_sort 0.000 0.002 0.012 0.084 quick_sort 0.000 0.002 0.020 0.197 shell_sort 0.002 0.018 0.234 2.897 insertion_sort 0.000 0.002 0.020 0.198 bubble_sort 0.064 6.328 --.--- --.--- Data ascending sequence: sort 0.000 0.000 0.002 0.020 radix_sort 0.001 0.010 0.128 1.546 quick_sort 0.004 0.058 0.521 5.996 shell_sort 0.001 0.019 0.234 2.882 insertion_sort 0.000 0.002 0.021 0.195 bubble_sort 0.065 6.453 --.--- --.--- Data randomly shuffled: sort 0.000 0.002 0.024 0.263 radix_sort 0.001 0.011 0.126 1.529 quick_sort 0.004 0.081 0.522 6.192 shell_sort 0.003 0.033 0.498 5.380 insertion_sort 0.027 2.627 --.--- --.--- bubble_sort 0.122 11.779 --.--- --.--- Data descending sequence: sort 0.000 0.001 0.001 0.021 radix_sort 0.001 0.012 0.125 1.560 quick_sort 0.004 0.061 0.522 5.873 shell_sort 0.003 0.028 0.316 3.829 insertion_sort 0.053 5.298 --.--- --.--- bubble_sort 0.206 17.232 --.--- --.---
Sidef
Array#sort is a built-in method.
class Array {
method radix_sort(base=10) {
var rounds = ([self.minmax].map{.abs}.max.ilog(base) + 1)
for i in (0..rounds) {
var buckets = (2*base -> of {[]})
var base_i = base**i
for n in self {
var digit = idiv(n, base_i)%base
digit += base if (0 <= n)
buckets[digit].append(n)
}
self = buckets.flat
}
return self
}
func merge(left, right) {
var result = []
while (left && right) {
result << [right,left].min_by{.first}.shift
}
result + left + right
}
method merge_sort {
var len = self.len
len < 2 && return self
var (left, right) = self.part(len>>1)
left = left.merge_sort
right = right.merge_sort
merge(left, right)
}
method quick_sort {
self.len < 2 && return self
var p = self.rand # to avoid the worst cases
var g = self.group_by {|x| x <=> p }
(g{-1} \\ []).quick_sort + (g{0} \\ []) + (g{1} \\ []).quick_sort
}
method shell_sort {
var h = self.len
while (h >>= 1) {
range(h, self.end).each { |i|
var k = self[i]
var j
for (j = i; (j >= h) && (k < self[j - h]); j -= h) {
self[j] = self[j - h]
}
self[j] = k
}
}
return self
}
method insertion_sort {
{ |i|
var j = i
var k = self[i+1]
while ((j >= 0) && (k < self[j])) {
self[j+1] = self[j]
j--
}
self[j+1] = k
} * self.end
return self
}
method bubble_sort {
loop {
var swapped = false
{ |i|
if (self[i] > self[i+1]) {
self[i, i+1] = self[i+1, i]
swapped = true
}
} << ^self.end
swapped || break
}
return self
}
}
var data_size = [1e2, 1e3, 1e4, 1e5]
var data = []
data_size.each {|size|
var ary = @(1..size)
data << [size.of(1), ary, ary.shuffle, ary.reverse]
}
data = data.transpose
var data_type = ["set to all ones", "ascending sequence",
"randomly shuffled", "descending sequence"]
print("Array size: ")
say data_size.map{|size| "%9d" % size}.join
data.each_kv {|i, arys|
say "\nData #{data_type[i]}:"
[:sort, :radix_sort, :quick_sort, :merge_sort,
:shell_sort, :insertion_sort, :bubble_sort].each {|m|
printf("%20s ", m)
var timeout = false
arys.each {|ary|
if (!timeout) {
var t0 = Time.micro
ary.clone.(m)
printf(" %7.3f", (var t1 = (Time.micro - t0)))
timeout = true if (t1 > 1.5)
}
else {
print(" --.---")
}
}
say ''
}
}
- Output:
Array size: 100 1000 10000 100000 Data set to all ones: sort 0.000 0.001 0.011 0.104 radix_sort 0.003 0.026 0.249 2.957 quick_sort 0.004 0.003 0.029 0.298 merge_sort 0.009 0.112 1.269 17.426 shell_sort 0.006 0.164 2.092 --.--- insertion_sort 0.002 0.016 0.149 1.261 bubble_sort 0.001 0.007 0.064 0.647 Data ascending sequence: sort 0.000 0.001 0.011 0.109 radix_sort 0.006 0.063 0.739 9.657 quick_sort 0.006 0.080 0.865 9.578 merge_sort 0.008 0.102 1.178 14.079 shell_sort 0.006 0.091 1.441 16.398 insertion_sort 0.001 0.012 0.124 1.258 bubble_sort 0.001 0.006 0.063 0.628 Data randomly shuffled: sort 0.001 0.009 0.126 1.632 radix_sort 0.006 0.060 0.731 8.768 quick_sort 0.005 0.058 0.742 9.516 merge_sort 0.010 0.132 1.639 --.--- shell_sort 0.010 0.167 2.931 --.--- insertion_sort 0.019 1.989 --.--- --.--- bubble_sort 0.069 7.333 --.--- --.--- Data descending sequence: sort 0.000 0.001 0.012 0.129 radix_sort 0.006 0.061 0.732 8.926 quick_sort 0.005 0.061 0.720 8.712 merge_sort 0.008 0.097 1.148 13.456 shell_sort 0.008 0.133 1.910 --.--- insertion_sort 0.040 3.884 --.--- --.--- bubble_sort 0.092 8.819 --.--- --.---
Tcl
Background
The lsort
command is Tcl's built-in sorting engine. It is implemented in C as a mergesort, so while it is theoretically slower than quicksort, it is a stable sorting algorithm too, which produces results that tend to be less surprising in practice. This task will be matching it against multiple manually-implemented sorting procedures.
Observations
Obviously, the built-in compiled sort command will be much faster than any Tcl-coded implementation. The Tcl-coded mergesort is up to 3 orders of magnitude slower.
The shellsort implementation suffers, relative to other algorithms, in the case where the list is already sorted.
Code
###############################################################################
# measure and plot times
package require Tk
package require struct::list
namespace path ::tcl::mathfunc
proc create_log10_plot {title xlabel ylabel xs ys labels shapes colours} {
set w [toplevel .[clock clicks]]
wm title $w $title
pack [canvas $w.c -background white]
pack [canvas $w.legend -background white]
update
plot_log10 $w.c $w.legend $title $xlabel $ylabel $xs $ys $labels $shapes $colours
$w.c config -scrollregion [$w.c bbox all]
update
}
proc plot_log10 {canvas legend title xlabel ylabel xs ys labels shapes colours} {
global xfac yfac
set log10_xs [map {_ {log10 $_}} $xs]
foreach series $ys {
lappend log10_ys [map {_ {log10 $_}} $series]
}
set maxx [max {*}$log10_xs]
set yvalues [lsort -real [struct::list flatten $log10_ys]]
set firstInf [lsearch $yvalues Inf]
set maxy [lindex $yvalues [expr {$firstInf == -1 ? [llength $yvalues] - 1 : $firstInf - 1}]]
set xfac [expr {[winfo width $canvas] * 0.8/$maxx}]
set yfac [expr {[winfo height $canvas] * 0.8/$maxy}]
scale $canvas x 0 $maxx $xfac "log10($xlabel)"
scale $canvas y 0 $maxy $yfac "log10($ylabel)" $maxx $xfac
$legend create text 30 0 -text $title -anchor nw
set count 1
foreach series $log10_ys shape $shapes colour $colours label $labels {
plotxy $canvas $log10_xs $series $shape $colour
legenditem $legend [incr count] $shape $colour $label
}
}
proc map {lambda list} {
set res [list]
foreach item $list {lappend res [apply $lambda $item]}
return $res
}
proc legenditem {legend pos shape colour label} {
set y [expr {$pos * 15}]
$shape $legend 20 $y -fill $colour
$legend create text 30 $y -text $label -anchor w
}
# The actual plotting engine
proc plotxy {canvas _xs _ys shape colour} {
global xfac yfac
foreach x $_xs y $_ys {
if {$y < Inf} {
lappend xs $x
lappend ys $y
}
}
set coords [list]
foreach x $xs y $ys {
set coord_x [expr {$x*$xfac}]
set coord_y [expr {-$y*$yfac}]
$shape $canvas $coord_x $coord_y -fill $colour
lappend coords $coord_x $coord_y
}
$canvas create line $coords -smooth true
}
# Rescales the contents of the given canvas
proc scale {canvas direction from to fac label {other_to 0} {other_fac 0}} {
set f [expr {$from*$fac}]
set t [expr {$to*$fac}]
switch -- $direction {
x {
set f [expr {$from * $fac}]
set t [expr {$to * $fac}]
# create x-axis
$canvas create line $f 0 $t 0
$canvas create text $f 0 -anchor nw -text $from
$canvas create text $t 0 -anchor n -text [format "%.1f" $to]
$canvas create text [expr {($f+$t)/2}] 0 -anchor n -text $label
}
y {
set f [expr {$from * -$fac}]
set t [expr {$to * -$fac}]
# create y-axis
$canvas create line 0 $f 0 $t
$canvas create text 0 $f -anchor se -text $from
$canvas create text 0 $t -anchor e -text [format "%.1f" $to]
$canvas create text 0 [expr {($f+$t)/2}] -anchor e -text $label
# create gridlines
set xmax [expr {$other_to * $other_fac}]
for {set i 1} {$i < $to} {incr i} {
set y [expr {$i * -$fac}]
$canvas create line 0 $y $xmax $y -dash .
}
}
}
}
# Helper to make points, which are otherwise not a native item type
proc dot {canvas x y args} {
set id [$canvas create oval [expr {$x-3}] [expr {$y-3}] \
[expr {$x+3}] [expr {$y+3}]]
$canvas itemconfigure $id {*}$args
}
proc square {canvas x y args} {
set id [$canvas create rectangle [expr {$x-3}] [expr {$y-3}] \
[expr {$x+3}] [expr {$y+3}]]
$canvas itemconfigure $id {*}$args
}
proc cross {canvas x y args} {
set l1 [$canvas create line [expr {$x-3}] $y [expr {$x+3}] $y]
set l2 [$canvas create line $x [expr {$y-3}] $x [expr {$y+3}]]
$canvas itemconfigure $l1 {*}$args
$canvas itemconfigure $l2 {*}$args
}
proc x {canvas x y args} {
set l1 [$canvas create line [expr {$x-3}] [expr {$y-3}] [expr {$x+3}] [expr {$y+3}]]
set l2 [$canvas create line [expr {$x+3}] [expr {$y-3}] [expr {$x-3}] [expr {$y+3}]]
$canvas itemconfigure $l1 {*}$args
$canvas itemconfigure $l2 {*}$args
}
proc triangleup {canvas x y args} {
set id [$canvas create polygon $x [expr {$y-4}] \
[expr {$x+4}] [expr {$y+4}] \
[expr {$x-4}] [expr {$y+4}]]
$canvas itemconfigure $id {*}$args
}
proc triangledown {canvas x y args} {
set id [$canvas create polygon $x [expr {$y+4}] \
[expr {$x+4}] [expr {$y-4}] \
[expr {$x-4}] [expr {$y-4}]]
$canvas itemconfigure $id {*}$args
}
wm withdraw .
#####################################################################
# list creation procedures
proc ones n {
lrepeat $n 1
}
proc reversed n {
while {[incr n -1] >= 0} {
lappend result $n
}
return $result
}
proc random n {
for {set i 0} {$i < $n} {incr i} {
lappend result [expr {int($n * rand())}]
}
return $result
}
set algorithms {lsort quicksort shellsort insertionsort bubblesort mergesort}
set sizes {1 10 100 1000 10000 100000}
set types {ones reversed random}
set shapes {dot square cross triangleup triangledown x}
set colours {red blue black brown yellow black}
# create some lists to be used by all sorting algorithms
array set lists {}
foreach size $sizes {
foreach type $types {
set lists($type,$size) [$type $size]
}
}
set runs 10
# header
fconfigure stdout -buffering none
puts -nonewline [format "%-16s" "list length:"]
foreach size $sizes {
puts -nonewline [format " %10d" $size]
}
puts ""
# perform the sort timings and output results
foreach type $types {
puts "\nlist type: $type"
set times [list]
foreach algo $algorithms {
set errs [list]
set thesetimes [list]
$algo {} ;# call it once to ensure it's compiled
puts -nonewline [format " %-13s" $algo]
foreach size $sizes {
# some implementations are just too slow
if {$type ne "ones" && (
($algo eq "insertionsort" && $size > 10000) ||
($algo eq "bubblesort" && $size > 1000))
} {
set time Inf
} else {
# OK, do it
if {[catch {time [list $algo $lists($type,$size)] $runs} result] != 0} {
set time Inf
lappend errs $result
} else {
set time [lindex [split $result] 0]
}
}
lappend thesetimes $time
puts -nonewline [format " %10s" $time]
}
puts ""
if {[llength $errs] > 0} {
puts [format " %s" [join $errs "\n "]]
}
lappend times $thesetimes
}
create_log10_plot "Sorting a '$type' list" size time $sizes $times $algorithms $shapes $colours
}
puts "\ntimes in microseconds, average of $runs runs"
Output
list length: 1 10 100 1000 10000 100000 list type: ones lsort 0.8 1.2 7.2 71.9 1042.7 11428.9 quicksort 1.1 9.0 40.6 369.5 3696.4 37478.4 shellsort 1.4 26.0 249.1 4003.4 56278.7 717790.6 insertionsort 1.1 6.4 59.0 528.1 5338.9 54913.0 bubblesort 1.9 5.1 31.9 308.8 3259.1 31991.2 mergesort 1.3 61.1 704.2 9275.4 224784.4 14599414.6 list type: reversed lsort 1.0 1.6 9.9 112.1 1434.9 20181.0 quicksort 1.5 55.3 495.6 6705.9 79984.0 963975.0 shellsort 1.5 25.9 457.0 7118.6 92497.5 1210143.9 insertionsort 1.2 21.0 1645.0 159262.2 15859610.8 Inf bubblesort 1.9 445.0 46526.6 4665550.4 Inf Inf mergesort 1.4 61.7 842.8 9572.1 215536.6 16938651.0 list type: random lsort 1.0 1.7 15.7 300.9 3275.0 58779.5 quicksort 1.2 28.0 429.1 5609.5 71743.3 923630.4 shellsort 1.6 26.7 571.0 9031.1 140526.9 2244152.7 insertionsort 1.3 15.4 832.6 79018.0 7893722.6 Inf bubblesort 1.8 256.2 23753.1 2422926.0 Inf Inf mergesort 1.9 60.2 883.5 12505.6 399672.6 49225509.8 times in microseconds, average of 10 runs
Wren
The quick, insertion and shell sorts all use the 'in place' implementations in the Wren-sort module.
The radix sort is lifted from the task of that name and, although more complicated, appears to be much faster than the Kotlin version.
For the bubble sort, I have used the optimized Kotlin implementation.
I've limited the size of the arrays to 50,000 though even then the program takes the best part of half an hour to run, due to the extreme slowness of the bubble and insertion sorts for large amounts of shuffled data.
Results presented in tabular form as Wren doesn't have a plotting library available at the present time.
import "random" for Random
import "./sort" for Sort
import "./fmt" for Fmt
var rand = Random.new()
var onesSeq = Fn.new { |n| List.filled(n, 1) }
var shuffledSeq = Fn.new { |n|
var seq = List.filled(n, 0)
for (i in 0...n) seq[i] = 1 + rand.int(10 * n)
return seq
}
var ascendingSeq = Fn.new { |n|
var seq = shuffledSeq.call(n)
seq.sort()
return seq
}
var bubbleSort = Fn.new { |a|
var n = a.count
while (true) {
var n2 = 0
for (i in 1...n) {
if (a[i - 1] > a[i]) {
a.swap(i, i - 1)
n2 = i
}
}
n = n2
if (n == 0) break
}
}
// counting sort of 'a' according to the digit represented by 'exp'
var countSort = Fn.new { |a, exp|
var n = a.count
var output = [0] * n
var count = [0] * 10
for (i in 0...n) {
var t = (a[i]/exp).truncate % 10
count[t] =