Sorting algorithms/Bubble sort
In this task, the goal is to sort an array of elements using the bubble sort algorithm. The elements must have a total order and the index of the array can be of any discrete type. For languages where this is not possible, sort an array of integers.
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
The bubble sort is generally considered to be the simplest sorting algorithm. Because of its simplicity and ease of visualization, it is often taught in introductory computer science courses. Because of its abysmal O(n2) performance, it is not used often for large (or even medium-sized) datasets.
The bubble sort works by passing sequentially over a list, comparing each value to the one immediately after it. If the first value is greater than the second, their positions are switched. Over a number of passes, at most equal to the number of elements in the list, all of the values drift into their correct positions (large values "bubble" rapidly toward the end, pushing others down around them). Because each pass finds the maximum item and puts it at the end, the portion of the list to be sorted can be reduced at each pass. A boolean variable is used to track whether any changes have been made in the current pass; when a pass completes without changing anything, the algorithm exits.
This can be expressed in pseudocode as follows (assuming 1-based indexing):
repeat
hasChanged := false
decrement itemCount
repeat with index from 1 to itemCount
if (item at index) > (item at (index + 1))
swap (item at index) with (item at (index + 1))
hasChanged := true
until hasChanged = false
- References
- The article on Wikipedia.
- Dance interpretation.
360 Assembly
For maximum compatibility, this program uses only the basic instruction set. <lang 360 Assembly>* Bubble Sort BUBBLE CSECT
USING BUBBLE,R13,R12
SAVEAREA B STM-SAVEAREA(R15) skip savearea
DC 17F'0'
DC CL8'BUBBLE'
STM STM R14,R12,12(R13) save calling context
ST R13,4(R15)
ST R15,8(R13)
LR R13,R15 set addessability
LA R12,4095(R13)
LA R12,1(R12)
MORE EQU *
LA R8,0 R8=no more
LA R1,A R1=Addr(A(I))
LA R2,2(R1) R2=Addr(A(I+1))
LA R4,0 to start at 1
LA R6,1 increment
L R7,N R7=N
BCTR R7,0 R7=N-1
LOOP BXH R4,R6,ENDLOOP for R4=1 to N-1
LH R3,0(R1) R3=A(I)
CH R3,0(R2) A(I)::A(I+1)
BNH NOSWAP if A(I)<=A(I+1) then goto NOSWAP
LH R9,0(R1) R9=A(I)
LH R3,0(R2) R3=A(I+1)
STH R3,0(R1) A(I)=R3
STH R9,0(R2) A(I+1)=R9
LA R8,1 R8=more
NOSWAP EQU *
LA R1,2(R1) next A(I)
LA R2,2(R2) next A(I+1)
B LOOP
ENDLOOP EQU *
LTR R8,R8
BNZ MORE
LA R3,A R3=Addr(A(I))
LA R4,0 to start at 1
LA R6,1 increment
L R7,N
PRNT BXH R4,R6,ENDPRNT for R4=1 to N
LH R5,0(R3) R5=A(I)
CVD R4,P Store I to packed P
UNPK Z,P Z=P
MVC C,Z C=Z
OI C+L'C-1,X'F0' ZAP SIGN
MVC BUFFER(4),C+12
CVD R5,P Store A(I) to packed P
UNPK Z,P Z=P
MVC C,Z C=Z
OI C+L'C-1,X'F0' ZAP SIGN
MVC BUFFER+10(6),C+10
WTO MF=(E,WTOMSG)
LA R3,2(R3) next A(I)
B PRNT
ENDPRNT EQU *
CNOP 0,4
L R13,4(0,R13)
LM R14,R12,12(R13) restore context
XR R15,R15 set return code to 0
BR R14 return to caller
N DC A((AEND-A)/2) number of items in A, so N=F'80' A DC H'223',H'356',H'018',H'820',H'664',H'845',H'927',H'198' 8
DC H'261',H'802',H'523',H'982',H'242',H'192',H'913',H'230' 16
DC H'353',H'565',H'195',H'174',H'665',H'807',H'050',H'539' 24
DC H'436',H'249',H'848',H'010',H'006',H'794',H'100',H'433' 32
DC H'782',H'728',H'259',H'358',H'206',H'081',H'701',H'997' 40
DC H'880',H'520',H'780',H'293',H'861',H'942',H'735',H'091' 48
DC H'503',H'582',H'716',H'836',H'135',H'653',H'856',H'142' 56
DC H'919',H'498',H'303',H'894',H'536',H'211',H'539',H'986' 64
DC H'356',H'796',H'644',H'552',H'771',H'443',H'035',H'780' 72
DC H'474',H'278',H'332',H'949',H'351',H'282',H'558',H'904' 80
AEND EQU * P DS PL8 packed Z DS ZL16 zoned C DS CL16 character WTOMSG CNOP 0,4
DC H'80' length of WTO buffer
DC H'0' must be binary zeroes
BUFFER DC 80C' '
LTORG
YREGS
END BUBBLE</lang>
- Output:
0001 000006 0002 000010 0003 000018 0004 000035 0005 000050 0006 000081 0007 000091 0008 000100 0009 000135 0010 000142 0011 000174 0012 000192 0013 000195 0014 000198 0015 000206 0016 000211 0017 000223 0018 000230 0019 000242 0020 000249 0021 000259 0022 000261 0023 000278 0024 000282 0025 000293 0026 000303 0027 000332 0028 000351 0029 000353 0030 000356 0031 000356 0032 000358 0033 000433 0034 000436 0035 000443 0036 000474 0037 000498 0038 000503 0039 000520 0040 000523 0041 000536 0042 000539 0043 000539 0044 000552 0045 000558 0046 000565 0047 000582 0048 000644 0049 000653 0050 000664 0051 000665 0052 000701 0053 000716 0054 000728 0055 000735 0056 000771 0057 000780 0058 000780 0059 000782 0060 000794 0061 000796 0062 000802 0063 000807 0064 000820 0065 000836 0066 000845 0067 000848 0068 000856 0069 000861 0070 000880 0071 000894 0072 000904 0073 000913 0074 000919 0075 000927 0076 000942 0077 000949 0078 000982 0079 000986 0080 000997
ACL2
<lang Lisp>(defun bubble (xs)
(if (endp (rest xs))
(mv nil xs)
(let ((x1 (first xs))
(x2 (second xs)))
(if (> x1 x2)
(mv-let (_ ys)
(bubble (cons x1 (rest (rest xs))))
(declare (ignore _))
(mv t (cons x2 ys)))
(mv-let (has-changed ys)
(bubble (rest xs))
(mv has-changed (cons x1 ys)))))))
(defun bsort-r (xs limit)
(declare (xargs :measure (nfix limit)))
(if (zp limit)
xs
(mv-let (has-changed ys)
(bubble xs)
(if has-changed
(bsort-r ys (1- limit))
ys))))
(defun bsort (xs)
(bsort-r xs (len xs)))</lang>
ActionScript
<lang actionscript>public function bubbleSort(toSort:Array):Array { var changed:Boolean = false;
while (!changed) { changed = true;
for (var i:int = 0; i < toSort.length - 1; i++) { if (toSort[i] > toSort[i + 1]) { var tmp:int = toSort[i]; toSort[i] = toSort[i + 1]; toSort[i + 1] = tmp;
changed = false; } } }
return toSort; }</lang>
Ada
<lang ada>generic
type Element is private; with function "=" (E1, E2 : Element) return Boolean is <>; with function "<" (E1, E2 : Element) return Boolean is <>; type Index is (<>); type Arr is array (Index range <>) of Element;
procedure Bubble_Sort (A : in out Arr);
procedure Bubble_Sort (A : in out Arr) is
Finished : Boolean; Temp : Element;
begin
loop Finished := True; for J in A'First .. Index'Pred (A'Last) loop if A (Index'Succ (J)) < A (J) then Finished := False; Temp := A (Index'Succ (J)); A (Index'Succ (J)) := A (J); A (J) := Temp; end if; end loop; exit when Finished; end loop;
end Bubble_Sort;
-- Example of usage: with Ada.Text_IO; use Ada.Text_IO; with Bubble_Sort; procedure Main is
type Arr is array (Positive range <>) of Integer; procedure Sort is new Bubble_Sort (Element => Integer, Index => Positive, Arr => Arr); A : Arr := (1, 3, 256, 0, 3, 4, -1);
begin
Sort (A); for J in A'Range loop Put (Integer'Image (A (J))); end loop; New_Line;
end Main;</lang>
ALGOL 68
<lang algol68>MODE DATA = INT; PROC swap = (REF[]DATA slice)VOID: (
DATA tmp = slice[1]; slice[1] := slice[2]; slice[2] := tmp
);
PROC sort = (REF[]DATA array)VOID: (
BOOL sorted;
INT shrinkage := 0;
FOR size FROM UPB array - 1 BY -1 WHILE
sorted := TRUE;
shrinkage +:= 1;
FOR i FROM LWB array TO size DO
IF array[i+1] < array[i] THEN
swap(array[i:i+1]);
sorted := FALSE
FI
OD;
NOT sorted
DO SKIP OD
);
main:(
[10]INT random := (1,6,3,5,2,9,8,4,7,0);
printf(($"Before: "10(g(3))l$,random)); sort(random); printf(($"After: "10(g(3))l$,random))
)</lang>
- Output:
Before: +1 +6 +3 +5 +2 +9 +8 +4 +7 +0 After: +0 +1 +2 +3 +4 +5 +6 +7 +8 +9
ALGOL W
<lang algolw>begin
% As algol W does not allow overloading, we have to have type-specific %
% sorting procedures - this bubble sorts an integer array %
% as there is no way for the procedure to determine the array bounds, we %
% pass the lower and upper bounds in lb and ub %
procedure bubbleSortIntegers( integer array item( * )
; integer value lb
; integer value ub
) ;
begin
integer lower, upper;
lower := lb;
upper := ub;
while
begin
logical swapped;
upper := upper - 1;
swapped := false;
for i := lower until upper
do begin
if item( i ) > item( i + 1 )
then begin
integer val;
val := item( i );
item( i ) := item( i + 1 );
item( i + 1 ) := val;
swapped := true;
end if_must_swap ;
end for_i ;
swapped
end
do begin end;
end bubbleSortIntegers ;
begin % test the bubble sort %
integer array data( 1 :: 10 );
procedure writeData ;
begin
write( data( 1 ) );
for i := 2 until 10 do writeon( data( i ) );
end writeData ;
% initialise data to unsorted values %
integer dPos;
dPos := 1;
for i := 16, 2, -6, 9, 90, 14, 0, 23, 8, 9
do begin
data( dPos ) := i;
dPos := dPos + 1;
end for_i ;
i_w := 3; s_w := 1; % set output format %
writeData;
bubbleSortIntegers( data, 1, 10 );
writeData;
end test
end.</lang>
- Output:
16 2 -6 9 90 14 0 23 8 9 -6 0 2 8 9 9 14 16 23 90
Arendelle
A function that returns a sorted version of it's x input
< x > ( i , 0 )
( sjt , 1; 0; 0 ) // swapped:0 / j:1 / temp:2
[ @sjt = 1 ,
( sjt , 0 )
( sjt[ 1 ] , +1 )
( i , 0 )
[ @i < @x? - @sjt[ 1 ],
{ @x[ @i ] < @x[ @i + 1 ],
( sjt[ 2 ] , @x[ @i ] )
( x[ @i ] , @x[ @i + 1 ] )
( x[ @i + 1 ] , @sjt[ 2 ] )
( sjt , 1 )
}
( i , +1 )
]
]
( return , @x )
AutoHotkey
<lang AutoHotkey>var = ( dog cat pile abc ) MsgBox % bubblesort(var)
bubblesort(var) ; each line of var is an element of the array {
StringSplit, array, var, `n
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% . "`n"
Return sorted
}</lang>
AWK
Sort the standard input and print it to standard output. <lang awk>{ # read every line into an array
line[NR] = $0
} END { # sort it with bubble sort
do {
haschanged = 0
for(i=1; i < NR; i++) {
if ( line[i] > line[i+1] ) {
t = line[i] line[i] = line[i+1] line[i+1] = t haschanged = 1
}
}
} while ( haschanged == 1 )
# print it
for(i=1; i <= NR; i++) {
print line[i]
}
}</lang>
GNU awk contains built in functions for sorting, but POSIX Awk doesn't. Here is a generic bubble sort() implementation that you can copy/paste to your Awk programs. Adapted from the above example. Note that it is not possible to return arrays from Awk functions so the array is "edited in place". The extra parameters passed in function's argument list is a well known trick to define local variables.
<lang awk>
- Test this example file from command line with:
- awk -f file.awk /dev/null
- Code by Jari Aalto <jari.aalto A T cante net>
- Licensed and released under GPL-2+, see http://spdx.org/licenses
function alen(array, dummy, len) {
for (dummy in array)
len++;
return len;
}
function sort(array, haschanged, len, tmp, i) {
len = alen(array) haschanged = 1
while ( haschanged == 1 )
{
haschanged = 0
for (i = 1; i <= len - 1; i++)
{
if (array[i] > array[i+1])
{
tmp = array[i]
array[i] = array[i + 1]
array[i + 1] = tmp
haschanged = 1
}
}
}
}
- An Example. Sorts array to order: b, c, z
{
array[1] = "c" array[2] = "z" array[3] = "b" sort(array) print array[1] " " array[2] " " array[3] exit
} </lang>
BASIC
Assume numbers are in a DIM of size "size" called "nums". <lang qbasic> DO
changed = 0
FOR I = 1 to size -1
IF nums(I) > nums(I + 1) THEN
tmp = nums(I)
nums(I) = nums(I + 1)
nums(I + 1) = tmp
changed = 1
END IF
NEXT
LOOP WHILE(NOT changed)</lang>
BASIC256
<lang basic256> Dim a(11): ordered=false print "Original set" For n = 0 to 9 a[n]=int(rand*20+1) print a[n]+", "; next n
- algorithm
while ordered=false
ordered=true
For n = 0 to 9
if a[n]> a[n+1] then
x=a[n]
a[n]=a[n+1]
a[n+1]=x
ordered=false
end if
next n
end while
print print "Ordered set" For n = 1 to 10 print a[n]+", "; next n </lang>
- Output:
(example)
Original set 2, 10, 17, 13, 20, 14, 3, 17, 16, 16, Ordered set 2, 3, 10, 13, 14, 16, 16, 17, 17, 20,
BBC BASIC
The Bubble sort is very inefficient for 99% of cases. This routine uses a couple of 'tricks' to try and mitigate the inefficiency to a limited extent. Note that the array index is assumed to start at zero. <lang bbcbasic> DIM test(9)
test() = 4, 65, 2, -31, 0, 99, 2, 83, 782, 1
PROCbubblesort(test(), 10)
FOR i% = 0 TO 9
PRINT test(i%) ;
NEXT
PRINT
END
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</lang>
- Output:
-31 0 1 2 2 4 65 83 99 782
C
<lang c>#include <stdio.h>
void bubble_sort (int *a, int n) {
int i, t, s = 1;
while (s) {
s = 0;
for (i = 1; i < n; i++) {
if (a[i] < a[i - 1]) {
t = a[i];
a[i] = a[i - 1];
a[i - 1] = t;
s = 1;
}
}
}
}
int main () {
int a[] = {4, 65, 2, -31, 0, 99, 2, 83, 782, 1};
int n = sizeof a / sizeof a[0];
int i;
for (i = 0; i < n; i++)
printf("%d%s", a[i], i == n - 1 ? "\n" : " ");
bubble_sort(a, n);
for (i = 0; i < n; i++)
printf("%d%s", a[i], i == n - 1 ? "\n" : " ");
return 0;
} </lang>
- Output:
4 65 2 -31 0 99 2 83 782 1 -31 0 1 2 2 4 65 83 99 782
C++
Uses C++11. Compile with
g++ -std=c++11 bubble.cpp
<lang cpp>#include <algorithm>
- include <iostream>
- include <iterator>
template <typename RandomAccessIterator> void bubble_sort(RandomAccessIterator begin, RandomAccessIterator end) {
bool swapped = true;
while (begin != end-- && swapped) {
swapped = false;
for (auto i = begin; i != end; ++i) {
if (*(i + 1) < *i) {
std::iter_swap(i, i + 1);
swapped = true;
}
}
}
}
int main() {
int a[] = {100, 2, 56, 200, -52, 3, 99, 33, 177, -199};
bubble_sort(std::begin(a), std::end(a));
copy(std::begin(a), std::end(a), std::ostream_iterator<int>(std::cout, " "));
std::cout << "\n";
}</lang>
- Output:
-199 -52 2 3 33 56 99 100 177 200
C#
<lang csharp>using System; using System.Collections.Generic;
namespace RosettaCode.BubbleSort {
public static class BubbleSortMethods
{
//The "this" keyword before the method parameter identifies this as a C# extension
//method, which can be called using instance method syntax on any generic list,
//without having to modify the generic List<T> code provided by the .NET framework.
public static void BubbleSort<T>(this List<T> list) where T : IComparable
{
bool madeChanges;
int itemCount = list.Count;
do
{
madeChanges = false;
itemCount--;
for (int i = 0; i < itemCount; i++)
{
if (list[i].CompareTo(list[i + 1]) > 0)
{
T temp = list[i + 1];
list[i + 1] = list[i];
list[i] = temp;
madeChanges = true;
}
}
} while (madeChanges);
}
}
//A short test program to demonstrate the BubbleSort. The compiler will change the
//call to testList.BubbleSort() into one to BubbleSortMethods.BubbleSort<T>(testList).
class Program
{
static void Main()
{
List<int> testList = new List<int> { 3, 7, 3, 2, 1, -4, 10, 12, 4 };
testList.BubbleSort();
foreach (var t in testList) Console.Write(t + " ");
}
}
}</lang>
Clojure
Bubble sorts a Java ArrayList in place. Uses 'doseq' iteration construct with a short-circuit when a pass didn't produce any change, and within the pass, an atomic 'changed' variable that gets reset whenever a change occurs.
<lang clojure>(ns bubblesort
(:import java.util.ArrayList))
(defn bubble-sort
"Sort in-place.
arr must implement the Java List interface and should support
random access, e.g. an ArrayList."
([arr] (bubble-sort compare arr))
([cmp arr]
(letfn [(swap! [i j]
(let [t (.get arr i)]
(doto arr
(.set i (.get arr j))
(.set j t))))
(sorter [stop-i]
(let [changed (atom false)]
(doseq [i (range stop-i)]
(if (pos? (cmp (.get arr i) (.get arr (inc i))))
(do
(swap! i (inc i))
(reset! changed true))))
@changed))]
(doseq [stop-i (range (dec (.size arr)) -1 -1)
:while (sorter stop-i)])
arr)))
(println (bubble-sort (ArrayList. [10 9 8 7 6 5 4 3 2 1])))</lang>
Purely functional version working on Clojure sequences: <lang clojure>(defn- bubble-step
"was-changed: whether any elements prior to the current first element were swapped; returns a two-element vector [partially-sorted-sequence is-sorted]" [less? xs was-changed] (if (< (count xs) 2) [xs (not was-changed)] (let [[x1 x2 & xr] xs
first-is-smaller (less? x1 x2) is-changed (or was-changed (not first-is-smaller)) [smaller larger] (if first-is-smaller [x1 x2] [x2 x1]) [result is-sorted] (bubble-step less? (cons larger xr) is-changed)]
[(cons smaller result) is-sorted])))
(defn bubble-sort
"Takes an optional less-than predicate and a sequence.
Returns the sorted sequence.
Very inefficient (O(n²))"
([xs] (bubble-sort <= xs))
([less? xs]
(let [[result is-sorted] (bubble-step less? xs false)]
(if is-sorted
result (recur less? result)))))
(println (bubble-sort [10 9 8 7 6 5 4 3 2 1]))</lang>
CMake
Only for lists of integers.
<lang cmake># bubble_sort(var [value1 value2...]) sorts a list of integers. function(bubble_sort var)
math(EXPR last "${ARGC} - 1") # Prepare to sort ARGV[1]..ARGV[last].
set(again YES)
while(again)
set(again NO)
math(EXPR last "${last} - 1") # Decrement last index.
foreach(index RANGE 1 ${last}) # Loop for each index.
math(EXPR index_plus_1 "${index} + 1")
set(a "${ARGV${index}}") # a = ARGV[index]
set(b "${ARGV${index_plus_1}}") # b = ARGV[index + 1]
if(a GREATER "${b}") # If a > b...
set(ARGV${index} "${b}") # ...then swap a, b
set(ARGV${index_plus_1} "${a}") # inside ARGV.
set(again YES)
endif()
endforeach(index)
endwhile()
set(answer)
math(EXPR last "${ARGC} - 1")
foreach(index RANGE 1 "${last}")
list(APPEND answer "${ARGV${index}}")
endforeach(index)
set("${var}" "${answer}" PARENT_SCOPE)
endfunction(bubble_sort)</lang>
<lang cmake>bubble_sort(result 33 11 44 22 66 55) message(STATUS "${result}")</lang>
-- 11;22;33;44;55;66
COBOL
This is a complete program that demonstrates the bubble sort algorithm in COBOL. <lang cobol>
identification division.
program-id. BUBBLSRT.
data division.
working-storage section.
01 changed-flag pic x.
88 hasChanged value 'Y'.
88 hasNOTChanged value 'N'.
01 itemCount pic 99.
01 tempItem pic 99.
01 itemArray.
03 itemArrayCount pic 99.
03 item pic 99 occurs 99 times
indexed by itemIndex.
*
procedure division.
main.
* place the values to sort into itemArray
move 10 to itemArrayCount
move 28 to item (1)
move 44 to item (2)
move 46 to item (3)
move 24 to item (4)
move 19 to item (5)
move 2 to item (6)
move 17 to item (7)
move 11 to item (8)
move 24 to item (9)
move 4 to item (10)
* store the starting count in itemCount and perform the sort
move itemArrayCount to itemCount
perform bubble-sort
* output the results
perform varying itemIndex from 1 by 1
until itemIndex > itemArrayCount
display item (itemIndex) ';' with no advancing
end-perform
* thats it!
stop run.
*
bubble-sort.
perform with test after until hasNOTchanged
set hasNOTChanged to true
subtract 1 from itemCount
perform varying itemIndex from 1 by 1
until itemIndex > itemCount
if item (itemIndex) > item (itemIndex + 1)
move item (itemIndex) to tempItem
move item (itemIndex + 1) to item (itemIndex)
move tempItem to item (itemIndex + 1)
set hasChanged to true
end-if
end-perform
end-perform
.
</lang>
- Output:
Output: 02;04;11;17;19;24;24;28;44;46;
Common Lisp
Bubble sort an sequence in-place, using the < operator for comparison if no comaprison function is provided <lang lisp>(defun bubble-sort (sequence &optional (compare #'<))
"sort a sequence (array or list) with an optional comparison function (cl:< is the default)"
(loop with sorted = nil until sorted do
(setf sorted t)
(loop for a below (1- (length sequence)) do
(unless (funcall compare (elt sequence a)
(elt sequence (1+ a)))
(rotatef (elt sequence a)
(elt sequence (1+ a)))
(setf sorted nil)))))</lang>
<lang lisp>(bubble-sort (list 5 4 3 2 1))</lang>
elt has linear access time for lists, making the prior implementation of bubble-sort very expensive (although very clear, and straightforward to code. Here is an implementation that works efficiently for both vectors and lists. For lists it also has the nice property that the input list and the sorted list begin with the same cons cell.
<lang lisp>(defun bubble-sort-vector (vector predicate &aux (len (1- (length vector))))
(do ((swapped t)) ((not swapped) vector)
(setf swapped nil)
(do ((i (min 0 len) (1+ i))) ((eql i len))
(when (funcall predicate (aref vector (1+ i)) (aref vector i))
(rotatef (aref vector i) (aref vector (1+ i)))
(setf swapped t)))))
(defun bubble-sort-list (list predicate)
(do ((swapped t)) ((not swapped) list)
(setf swapped nil)
(do ((list list (rest list))) ((endp (rest list)))
(when (funcall predicate (second list) (first list))
(rotatef (first list) (second list))
(setf swapped t)))))
(defun bubble-sort (sequence predicate)
(etypecase sequence (list (bubble-sort-list sequence predicate)) (vector (bubble-sort-vector sequence predicate))))</lang>
D
<lang d>import std.stdio, std.algorithm;
void bubbleSort(T)(T[] data) pure nothrow {
auto itemCount = data.length; bool hasChanged = false;
do {
hasChanged = false;
itemCount--;
foreach (immutable i; 0 .. itemCount)
if (data[i] > data[i + 1]) {
swap(data[i], data[i + 1]);
hasChanged = true;
}
} while (hasChanged);
}
void main() {
auto array = [28, 44, 46, 24, 19, 2, 17, 11, 25, 4]; array.bubbleSort(); writeln(array);
}</lang>
- Output:
[2, 4, 11, 17, 19, 24, 25, 28, 44, 46]
Delphi
Dynamic array is a 0-based array of variable length
Static array is an arbitrary-based array of fixed length <lang Delphi>program TestBubbleSort;
{$APPTYPE CONSOLE}
{.$DEFINE DYNARRAY} // remove '.' to compile with dynamic array
type
TItem = Integer; // declare ordinal type for array item
{$IFDEF DYNARRAY}
TArray = array of TItem; // dynamic array
{$ELSE}
TArray = array[0..15] of TItem; // static array
{$ENDIF}
procedure BubbleSort(var A: TArray); var
Item: TItem; K, L, J: Integer;
begin
L:= Low(A) + 1;
repeat
K:= High(A);
for J:= High(A) downto L do begin
if A[J - 1] > A[J] then begin
Item:= A[J - 1];
A[J - 1]:= A[J];
A[J]:= Item;
K:= J;
end;
end;
L:= K + 1;
until L > High(A);
end;
var
A: TArray; I: Integer;
begin {$IFDEF DYNARRAY}
SetLength(A, 16);
{$ENDIF}
for I:= Low(A) to High(A) do A[I]:= Random(100); for I:= Low(A) to High(A) do Write(A[I]:3); Writeln; BubbleSort(A); for I:= Low(A) to High(A) do Write(A[I]:3); Writeln; Readln;
end.</lang>
- Output:
0 3 86 20 27 67 31 16 37 42 8 47 7 84 5 29 0 3 5 7 8 16 20 27 29 31 37 42 47 67 84 86
E
<lang e>def bubbleSort(target) {
__loop(fn {
var changed := false
for i in 0..(target.size() - 2) {
def [a, b] := target(i, i + 2)
if (a > b) {
target(i, i + 2) := [b, a]
changed := true
}
}
changed
})
}</lang>
(Uses the primitive __loop directly because it happens to map to the termination test for this algorithm well.)
EchoLisp
<lang scheme>
- sorts a vector of objects in place
- proc is an user defined comparison procedure
(define (bubble-sort V proc) (define length (vector-length V))
(for* ((i (in-range 0 (1- length))) (j (in-range (1+ i) length))) (unless (proc (vector-ref V i) (vector-ref V j)) (vector-swap! V i j))) V)
(define V #( albert antoinette elvis zen simon))
(define (sort/length a b) ;; sort by string length
(< (string-length a) (string-length b)))
(bubble-sort V sort/length)
→ #(zen simon elvis albert antoinette)
</lang>
Eiffel
This solution is presented in two classes. The first is a simple application that creates a set, an instance of MY_SORTED_SET, and adds elements to the set in unsorted order. It iterates across the set printing the elements, then it sorts the set, and reprints the elements.
<lang eiffel>class
APPLICATION
create
make
feature
make
-- Create and print sorted set
do
create my_set.make
my_set.put_front (2)
my_set.put_front (6)
my_set.put_front (1)
my_set.put_front (5)
my_set.put_front (3)
my_set.put_front (9)
my_set.put_front (8)
my_set.put_front (4)
my_set.put_front (10)
my_set.put_front (7)
print ("Before: ")
across my_set as ic loop print (ic.item.out + " ") end
print ("%NAfter : ")
my_set.sort
across my_set as ic loop print (ic.item.out + " ") end
end
my_set: MY_SORTED_SET [INTEGER]
-- Set to be sorted
end</lang>
The second class is MY_SORTED_SET.
<lang eiffel>class
MY_SORTED_SET [G -> COMPARABLE]
inherit
TWO_WAY_SORTED_SET [G]
redefine
sort
end
create
make
feature
sort
-- Sort with bubble sort
local
l_unchanged: BOOLEAN
l_item_count: INTEGER
l_temp: G
do
from
l_item_count := count
until
l_unchanged
loop
l_unchanged := True
l_item_count := l_item_count - 1
across 1 |..| l_item_count as ic loop
if Current [ic.item] > Current [ic.item + 1] then
l_temp := Current [ic.item]
Current [ic.item] := Current [ic.item + 1]
Current [ic.item + 1] := l_temp
l_unchanged := False
end
end
end
end
end</lang>
This class inherits from the Eiffel library class TWO_WAY_SORTED_SET, which implements sets whose elements are comparable. Therefore, the set can be ordered and in fact is kept so under normal circumstances.
MY_SORTED_SET redefines only the routine sort which contains the implementation of the sort algorithm. The implementation in the redefined version of sort in MY_SORTED_SET uses a bubble sort.
- Output:
Before: 7 10 4 8 9 3 5 1 6 2 After : 1 2 3 4 5 6 7 8 9 10
TWO_WAY_SORTED_SET is implemented internally as a list.
For this example, we use the feature put_front which explicitly adds each new element to the beginning of the list, allowing us to show that the elements are unordered until we sort them.
It also causes, in the "Before" output, the elements to be printed in the reverse of the order in which they were added.
Under normal circumstances, we would use the feature extend (rather than put_front) to add elements to the list.
This would assure that the order was maintained even as elements were added.
Elixir
<lang elixir>defmodule Sort do
def bubble_sort(list) when length(list)<=1, do: list
def bubble_sort(list) when is_list(list), do: bubble_sort(list, [])
def bubble_sort([x], sorted), do: [x | sorted]
def bubble_sort(list, sorted) do
{rest, [max]} = Enum.split(bubble_move(list), -1)
bubble_sort(rest, [max | sorted])
end
def bubble_move([x]), do: [x]
def bubble_move([x, y | t]) when x > y, do: [y | bubble_move([x | t])]
def bubble_move([x, y | t]) , do: [x | bubble_move([y | t])]
end
IO.inspect Sort.bubble_sort([3,2,1,4,5,2])</lang>
- Output:
[1, 2, 2, 3, 4, 5]
Erlang
sort/3 copied from Stackoverflow. <lang Erlang> -module( bubble_sort ).
-export( [list/1, task/0] ).
list( To_be_sorted ) -> sort( To_be_sorted, [], true ).
task() -> List = "asdqwe123", Sorted = list( List ), io:fwrite( "List ~p is sorted ~p~n", [List, Sorted] ).
sort( [], Acc, true ) -> lists:reverse( Acc );
sort( [], Acc, false ) -> sort( lists:reverse(Acc), [], true );
sort( [X, Y | T], Acc, _Done ) when X > Y -> sort( [X | T], [Y | Acc], false );
sort( [X | T], Acc, Done ) -> sort( T, [X | Acc], Done ).
</lang>
- Output:
7> bubble_sort:task(). List "asdqwe123" is sorted "123adeqsw"
Euphoria
<lang euphoria>function bubble_sort(sequence s)
object tmp
integer changed
for j = length(s) to 1 by -1 do
changed = 0
for i = 1 to j-1 do
if compare(s[i], s[i+1]) > 0 then
tmp = s[i]
s[i] = s[i+1]
s[i+1] = tmp
changed = 1
end if
end for
if not changed then
exit
end if
end for
return s
end function
include misc.e constant s = {4, 15, "delta", 2, -31, 0, "alfa", 19, "gamma", 2, 13, "beta", 782, 1}
puts(1,"Before: ") pretty_print(1,s,{2}) puts(1,"\nAfter: ") pretty_print(1,bubble_sort(s),{2})</lang>
- Output:
Before: {
4,
15,
"delta",
2,
-31,
0,
"alfa",
19,
"gamma",
2,
13,
"beta",
782,
1
}
After: {
-31,
0,
1,
2,
2,
4,
13,
15,
19,
782,
"alfa",
"beta",
"delta",
"gamma"
}
Ezhil
<lang Ezhil>
- இந்த நிரல் ஒரு பட்டியலில் உள்ள எண்களை Bubble Sort என்ற முறைப்படி ஏறுவரிசையிலும் பின்னர் அதையே இறங்குவரிசையிலும் அடுக்கித் தரும்
- மாதிரிக்கு நாம் ஏழு எண்களை எடுத்துக்கொள்வோம்
எண்கள் = [5, 1, 10, 8, 1, 21, 4, 2] எண்கள்பிரதி = எண்கள்
பதிப்பி "ஆரம்பப் பட்டியல்:" பதிப்பி எண்கள்
நீளம் = len(எண்கள்) குறைநீளம் = நீளம் - 1
@(குறைநீளம் != -1) வரை
மாற்றம் = -1 @(எண் = 0, எண் < குறைநீளம், எண் = எண் + 1) ஆக முதலெண் = எடு(எண்கள், எண்) இரண்டாமெண் = எடு(எண்கள், எண் + 1) @(முதலெண் > இரண்டாமெண்) ஆனால்
## பெரிய எண்களை ஒவ்வொன்றாகப் பின்னே நகர்த்துகிறோம்
வெளியேஎடு(எண்கள், எண்)
நுழைக்க(எண்கள், எண், இரண்டாமெண்)
வெளியேஎடு(எண்கள், எண் + 1)
நுழைக்க(எண்கள், எண் + 1, முதலெண்)
மாற்றம் = எண்
முடி
முடி
குறைநீளம் = மாற்றம்
முடி
பதிப்பி "ஏறு வரிசையில் அமைக்கப்பட்ட பட்டியல்:" பதிப்பி எண்கள்
- இதனை இறங்குவரிசைக்கு மாற்றுவதற்கு எளிய வழி
தலைகீழ்(எண்கள்)
- இப்போது, நாம் ஏற்கெனவே எடுத்துவைத்த எண்களின் பிரதியை Bubble Sort முறைப்படி இறங்குவரிசைக்கு மாற்றுவோம்
நீளம் = len(எண்கள்பிரதி) குறைநீளம் = நீளம் - 1
@(குறைநீளம் != -1) வரை
மாற்றம் = -1 @(எண் = 0, எண் < குறைநீளம், எண் = எண் + 1) ஆக முதலெண் = எடு(எண்கள்பிரதி, எண்) இரண்டாமெண் = எடு(எண்கள்பிரதி, எண் + 1) @(முதலெண் < இரண்டாமெண்) ஆனால்
## சிறிய எண்களை ஒவ்வொன்றாகப் பின்னே நகர்த்துகிறோம்
வெளியேஎடு(எண்கள்பிரதி, எண்)
நுழைக்க(எண்கள்பிரதி, எண், இரண்டாமெண்)
வெளியேஎடு(எண்கள்பிரதி, எண் + 1)
நுழைக்க(எண்கள்பிரதி, எண் + 1, முதலெண்)
மாற்றம் = எண்
முடி
முடி
குறைநீளம் = மாற்றம்
முடி
பதிப்பி "இறங்கு வரிசையில் அமைக்கப்பட்ட பட்டியல்:" பதிப்பி எண்கள்பிரதி
</lang>
F#
<lang fsharp>let BubbleSort (lst : list<int>) =
let rec sort accum rev lst =
match lst, rev with
| [], true -> accum |> List.rev
| [], false -> accum |> List.rev |> sort [] true
| x::y::tail, _ when x > y -> sort (y::accum) false (x::tail)
| head::tail, _ -> sort (head::accum) rev tail
sort [] true lst
</lang>
Factor
<lang factor>USING: fry kernel locals math math.order sequences sequences.private ; IN: rosetta.bubble
<PRIVATE
- ?exchange ( i seq quot -- ? )
i i 1 + [ seq nth-unsafe ] bi@ quot call +gt+ = :> doit? doit? [ i i 1 + seq exchange ] when doit? ; inline
- 1pass ( seq quot -- ? )
[ [ length 1 - iota ] keep ] dip '[ _ _ ?exchange ] [ or ] map-reduce ; inline
PRIVATE>
- sort! ( seq quot -- )
over empty? [ 2drop ] [ '[ _ _ 1pass ] loop ] if ; inline
- natural-sort! ( seq -- )
[ <=> ] sort! ;</lang>
It is possible to pass your own comparison operator to sort!, so you can f.e. sort your sequence backwards with passing [ >=< ] into it.
<lang factor>10 [ 10000 random ] replicate [ "Before: " write . ] [ "Natural: " write [ natural-sort! ] keep . ] [ "Reverse: " write [ [ >=< ] sort! ] keep . ] tri</lang>
Before: { 3707 5045 4661 1489 3140 7195 8844 6506 6322 3199 }
Natural: { 1489 3140 3199 3707 4661 5045 6322 6506 7195 8844 }
Reverse: { 8844 7195 6506 6322 5045 4661 3707 3199 3140 1489 }
Fish
This is not a complete implementation of bubblesort: it doesn't keep a boolean flag whether to stop, so it goes on printing each stage of the sorting process ad infinitum.
<lang fish>v Sorts the (pre-loaded) stack
with bubblesort.
v < \l0=?;l& >&:1=?v1-&2[$:{:{](?${
>~{ao ^
>~}l &{ v
o","{n:&-1^?=0:&<</lang>
Forth
Sorts the 'cnt' cells stored at 'addr' using the test stored in the deferred word 'bubble-test'. Uses forth local variables for clarity.
<lang forth>defer bubble-test ' > is bubble-test
- bubble { addr cnt -- }
cnt 1 do
addr cnt i - cells bounds do
i 2@ bubble-test if i 2@ swap i 2! then
cell +loop
loop ;</lang>
This is the same algorithm done without the local variables:
<lang forth>: bubble ( addr cnt -- )
dup 1 do
2dup i - cells bounds do
i 2@ bubble-test if i 2@ swap i 2! then
cell +loop
loop ;</lang>
Version with O(n) best case: <lang forth>: bubble ( addr len -- )
begin
1- 2dup true -rot ( sorted addr len-1 )
cells bounds ?do
i 2@ bubble-test if
i 2@ swap i 2!
drop false ( mark unsorted )
then
cell +loop ( sorted )
until 2drop ;</lang>
Test any version with this:
create test 8 , 1 , 4 , 2 , 10 , 3 , 7 , 9 , 6 , 5 , here test - cell / constant tcnt test tcnt cells dump ' > is bubble-test test tcnt bubble test tcnt cells dump ' < is bubble-test test tcnt bubble test tcnt cells dump
Fortran
<lang fortran>SUBROUTINE Bubble_Sort(a)
REAL, INTENT(in out), DIMENSION(:) :: a
REAL :: temp
INTEGER :: i, j
LOGICAL :: swapped
DO j = SIZE(a)-1, 1, -1
swapped = .FALSE.
DO i = 1, j
IF (a(i) > a(i+1)) THEN
temp = a(i)
a(i) = a(i+1)
a(i+1) = temp
swapped = .TRUE.
END IF
END DO
IF (.NOT. swapped) EXIT
END DO
END SUBROUTINE Bubble_Sort</lang>
FreeBASIC
Per task pseudo code: <lang FreeBASIC>' version 21-06-2015 ' compile with: fbc -s console ' for boundry checks on array's compile with: fbc -s console -exx
Sub bubblesort(bs() As Integer)
' sort from lower bound to the highter bound ' array's can have subscript range from -2147483648 to +2147483647 Dim As Integer lb = LBound(bs) Dim As Integer ub = UBound(bs) -1 Dim As Integer done, i
Do
done = 0
For i = lb To ub
' replace "<" with ">" for downwards sort
If bs(i) > bs(i + 1) Then
Swap bs(i), bs(i + 1)
done = 1
End If
Next
ub = ub -1
Loop Until done = 0
End Sub
' ------=< MAIN >=------
Dim As Integer i, array(-7 To 7)
Dim As Integer a = LBound(array), b = UBound(array)
Randomize Timer For i = a To b : array(i) = i : Next For i = a To b ' little shuffle
Swap array(i), array(Rnd * b)
Next
Print "unsort "; For i = a To b : Print Using "####"; array(i); : Next : Print bubblesort(array()) ' sort the array Print " sort "; For i = a To b : Print Using "####"; array(i); : Next : Print
' empty keyboard buffer While InKey <> "" : Var _key_ = InKey : Wend Print : Print "hit any key to end program" Sleep End</lang>
- Output:
unsort 6 2 4 7 1 5 -6 -2 3 -4 -7 -3 -1 -5 0 sort -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7
Go
Per task pseudocode: <lang go>package main
import "fmt"
func main() {
list := []int{31, 41, 59, 26, 53, 58, 97, 93, 23, 84}
fmt.Println("unsorted:", list)
bubblesort(list)
fmt.Println("sorted! ", list)
}
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
}
}
}</lang>
More generic version that can sort anything that implements sort.Interface:
<lang go>package main
import (
"sort" "fmt"
)
func main() {
list := []int{31, 41, 59, 26, 53, 58, 97, 93, 23, 84}
fmt.Println("unsorted:", list)
bubblesort(sort.IntSlice(list))
fmt.Println("sorted! ", list)
}
func bubblesort(a sort.Interface) {
for itemCount := a.Len() - 1; ; itemCount-- {
hasChanged := false
for index := 0; index < itemCount; index++ {
if a.Less(index+1, index) {
a.Swap(index, index+1)
hasChanged = true
}
}
if !hasChanged {
break
}
}
}</lang>
Groovy
Solution: <lang groovy>def makeSwap = { a, i, j = i+1 -> print "."; ai,j = aj,i }
def checkSwap = { a, i, j = i+1 -> [(a[i] > a[j])].find { it }.each { makeSwap(a, i, j) } }
def bubbleSort = { list ->
boolean swapped = true
while (swapped) { swapped = (1..<list.size()).any { checkSwap(list, it-1) } }
list
}</lang>
Test Program: <lang groovy>println bubbleSort([23,76,99,58,97,57,35,89,51,38,95,92,24,46,31,24,14,12,57,78,4]) println bubbleSort([88,18,31,44,4,0,8,81,14,78,20,76,84,33,73,75,82,5,62,70,12,7,1])</lang>
- Output:
..............................................................................................................................................[4, 12, 14, 23, 24, 24, 31, 35, 38, 46, 51, 57, 57, 58, 76, 78, 89, 92, 95, 97, 99] .........................................................................................................................................[0, 1, 4, 5, 7, 8, 12, 14, 18, 20, 31, 33, 44, 62, 70, 73, 75, 76, 78, 81, 82, 84, 88]
Haskell
This version checks for changes in a separate step for simplicity, because Haskell has no variables to track them with. <lang haskell>bsort :: Ord a => [a] -> [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</lang>
This version uses the polymorphic Maybe type to designate unchanged lists. (The type signature of _bsort is now Ord a => [a] -> Maybe [a].) It is slightly faster than the previous one.
<lang haskell>import Data.Maybe (fromMaybe) import Control.Monad
bsort :: Ord a => [a] -> [a] bsort s = maybe s bsort $ _bsort s
where _bsort (x:x2:xs) = if x > x2
then Just $ x2 : fromMaybe (x:xs) (_bsort $ x:xs)
else liftM (x:) $ _bsort (x2:xs)
_bsort _ = Nothing</lang>
This version is based on the above, but avoids sorting whole list each time. To implement this without a counter and retain using pattern matching, inner sorting is reversed, and then result is reversed back. Sorting is based on a predicate, e. g. (<) or (>).
<lang haskell>import Data.Maybe (fromMaybe) import Control.Monad
bubbleSortBy :: (a -> a -> Bool) -> [a] -> [a] bubbleSortBy f as = case innerSort $ reverse as of
Nothing -> as
Just v -> let (x:xs) = reverse v
in x : bubbleSortBy f xs
where innerSort (a:b:cs) = if b `f` a
then liftM (a:) $ innerSort (b:cs)
else Just $ b : fromMaybe (a:cs)
(innerSort $ a:cs)
innerSort _ = Nothing
bsort :: Ord a => [a] -> [a] bsort = bubbleSortBy (<)</lang>
HicEst
<lang fortran>SUBROUTINE Bubble_Sort(a)
REAL :: a(1)
DO j = LEN(a)-1, 1, -1
swapped = 0
DO i = 1, j
IF (a(i) > a(i+1)) THEN
temp = a(i)
a(i) = a(i+1)
a(i+1) = temp
swapped = 1
ENDIF
ENDDO
IF (swapped == 0) RETURN
ENDDO
END</lang>
Icon and Unicon
Icon/Unicon implementation of a bubble sort <lang Icon>procedure main() #: demonstrate various ways to sort a list and string
demosort(bubblesort,[3, 14, 1, 5, 9, 2, 6, 3],"qwerty")
end
procedure bubblesort(X,op) #: return sorted list local i,swapped
op := sortop(op,X) # select how and what we sort
swapped := 1
while \swapped := &null do # the sort
every i := 2 to *X do
if op(X[i],X[i-1]) then
X[i-1] :=: X[swapped := i]
return X
end</lang>
- Output:
Sorting Demo using procedure bubblesort
on list : [ 3 14 1 5 9 2 6 3 ]
with op = &null: [ 1 2 3 3 5 6 9 14 ] (0 ms)
with op = "numeric": [ 1 2 3 3 5 6 9 14 ] (0 ms)
with op = "string": [ 1 14 2 3 3 5 6 9 ] (0 ms)
with op = ">>": [ 9 6 5 3 3 2 14 1 ] (0 ms)
with op = ">": [ 14 9 6 5 3 3 2 1 ] (0 ms)
with op = procedure cmp: [ 1 2 3 3 5 6 9 14 ] (1 ms)
with op = "cmp": [ 1 2 3 3 5 6 9 14 ] (0 ms)
on string : "qwerty"
with op = &null: "eqrtwy" (0 ms)
The following code supports this and other sorting demonstrations.
- Sorting illustrates a difference in the way Icon and Unicon handles data types. Built-in operators for comparing data types make a syntactic distinction between numeric and string types, and sorting structured and user-defined types require custom code. An added complication arises because mixed types are allowed. Two approaches are possible here: (1) that taken by the built-in sort which sorts first by type and then value The sort order of types is: &null, integer, real, string, cset, procedure, list, set, table, and record; and (2) Coercion of types which is used here (and implemented in 'sortop') to decide on using string or numeric sorting. These sorts will not handle more exotic type mixes.
- The 'sortop' procedure allows various methods of comparison be selected including customized ones. The example could be made more general to deal with coercion of types like cset to string (admittedly an uninteresting example as csets are already sorted). Custom comparators are shown by and example procedure 'cmp'.
- 'demosort' can apply different sorting procedures and operators to lists and strings to show how this works. The routines 'displaysort' and 'writex' are helpers.
<lang icon>invocable all # for op
procedure sortop(op,X) #: select how to sort
op := case op of {
"string": "<<"
"numeric": "<"
&null: if type(!X) == "string" then "<<" else "<"
default: op
}
return proc(op, 2) | runerr(123, image(op)) end
procedure cmp(a,b) #: example custom comparison procedure
return a < b # Imagine a complex comparison test here!
end
procedure demosort(sortproc,L,s) # demonstrate sort on L and s
write("Sorting Demo using ",image(sortproc))
writes(" on list : ")
writex(L)
displaysort(sortproc,L) # default string sort
displaysort(sortproc,L,"numeric") # explicit numeric sort
displaysort(sortproc,L,"string") # explicit string sort
displaysort(sortproc,L,">>") # descending string sort
displaysort(sortproc,L,">") # descending numeric sort
displaysort(sortproc,L,cmp) # ascending custom comparison
displaysort(sortproc,L,"cmp") # ascending custom comparison
writes(" on string : ")
writex(s)
displaysort(sortproc,s) # sort characters in a string
write()
return
end
procedure displaysort(sortproc,X,op) #: helper to show sort behavior local t,SX
writes(" with op = ",left(image(op)||":",15))
X := copy(X)
t := &time
SX := sortproc(X,op)
writex(SX," (",&time - t," ms)")
return
end
procedure writex(X,suf[]) #: helper for displaysort
if type(X) == "string" then
writes(image(X))
else {
writes("[")
every writes(" ",image(!X))
writes(" ]")
}
every writes(!suf)
write()
return end</lang>
J
<lang j>bubbleSort=: (([ (<. , >.) {.@]) , }.@])/^:_</lang>
Test program:
<lang j> ?. 10 $ 10 4 6 8 6 5 8 6 6 6 9
bubbleSort ?. 10 $ 10
4 5 6 6 6 6 6 8 8 9</lang>
For the most part, bubble sort works against J's strengths. However, once a single pass has been implemented as a list operation, ^:_ tells J to repeat this until the result stops changing.
Java
Bubble sorting (ascending) an array of any Comparable type: <lang java>public static <E extends Comparable<? super E>> void bubbleSort(E[] comparable) {
boolean changed = false;
do {
changed = false;
for (int a = 0; a < comparable.length - 1; a++) {
if (comparable[a].compareTo(comparable[a + 1]) > 0) {
E tmp = comparable[a];
comparable[a] = comparable[a + 1];
comparable[a + 1] = tmp;
changed = true;
}
}
} while (changed);
}</lang>
For descending, simply switch the direction of comparison: <lang java>if (comparable[a].compareTo(comparable[b]) < 0){
//same swap code as before
}</lang>
JavaScript
<lang javascript>Array.prototype.bubblesort = function() {
var done = false;
while (!done) {
done = true;
for (var i = 1; i<this.length; i++) {
if (this[i-1] > this[i]) {
done = false;
[this[i-1], this[i]] = [this[i], this[i-1]]
}
}
}
return this;
}</lang>
<lang javascript>Array.prototype.bubblesort = function() {
var done = false;
while (! done) {
done = true;
for (var i = 1; i < this.length; i++) {
if (this[i - 1] > this[i]) {
done = false;
var tmp = this[i - 1];
this[i - 1] = this[i];
this[i] = tmp;
}
}
}
return this;
}</lang>
Example: <lang javascript>var my_arr = ["G", "F", "C", "A", "B", "E", "D"]; my_arr.bubblesort(); print(my_arr);</lang>
- Output:
A,B,C,D,E,F,G
jq
<lang jq>def bubble_sort:
def swap(i;j): .[i] as $x | .[i]=.[j] | .[j]=$x;
# input/output: [changed, list]
reduce range(0; length) as $i
( [false, .];
if $i > 0 and (.[0]|not) then .
else reduce range(0; (.[1]|length) - $i - 1) as $j
(.[0] = false;
.[1] as $list
| if $list[$j] > $list[$j + 1] then [true, ($list|swap($j; $j+1))]
else .
end )
end ) | .[1] ;</lang>
Example: <lang jq>(
[3,2,1], [1,2,3], ["G", "F", "C", "A", "B", "E", "D"]
) | bubble_sort</lang>
- Output:
<lang sh>$ jq -c -n -f Bubble_sort.jq [1,2,3] [1,2,3] ["A","B","C","D","E","F","G"]</lang>
Julia
<lang Julia> function bubblesort{T}(a::AbstractArray{T,1})
b = copy(a)
isordered = false
span = length(b)
while !isordered && span > 1
isordered = true
for i in 2:span
if b[i] < b[i-1]
t = b[i]
b[i] = b[i-1]
b[i-1] = t
isordered = false
end
end
span -= 1
end
return b
end
a = [rand(-100:100) for i in 1:20] println("Before bubblesort:") println(a) a = bubblesort(a) println("\nAfter bubblesort:") println(a) </lang>
- Output:
Before bubblesort: [95,-40,-93,38,95,-20,-13,-61,81,51,-54,77,-4,-49,-99,-55,28,-52,2,-28] After bubblesort: [-99,-93,-61,-55,-54,-52,-49,-40,-28,-20,-13,-4,2,28,38,51,77,81,95,95]
Here bubblesort was used on a list of integers. As written the function will work on lists of any objects for which isless is defined.
Kotlin
<lang kotlin>fun <T> bubbleSort(a : Array<T>, c: Comparator<T>) {
var changed : Boolean
do {
changed = false
for (i in 0 .. a.size - 2) {
if (c.compare(a[i], a[i + 1]) > 0) {
val tmp = a[i]
a[i] = a[i + 1]
a[i + 1] = tmp
changed = true
}
}
} while (changed)
}</lang>
Io
<lang Io> List do(
bubblesort := method(
t := true
while( t,
t := false
for( j, 0, self size - 2,
if( self at( j ) start > self at( j+1 ) start,
self swapIndices( j,j+1 )
t := true
)
)
)
return( self )
)
) </lang>
Liberty BASIC
<lang lb>
itemCount = 20
dim item(itemCount)
for i = 1 to itemCount
item(i) = int(rnd(1) * 100)
next i
print "Before Sort"
for i = 1 to itemCount
print item(i)
next i
print: print
counter = itemCount
do
hasChanged = 0
for i = 1 to counter - 1
if item(i) > item(i + 1) then
temp = item(i)
item(i) = item(i + 1)
item(i + 1) = temp
hasChanged = 1
end if
next i
counter =counter -1
loop while hasChanged = 1
print "After Sort"
for i = 1 to itemCount
print item(i)
next i
end </lang>
Lisaac
<lang Lisaac>Section Header
+ name := BUBBLE_SORT;
- external := `#include <time.h>`;
Section Public
- main <- (
+ a : ARRAY(INTEGER);
a := ARRAY(INTEGER).create 0 to 100;
`srand(time(NULL))`;
0.to 100 do { i : INTEGER;
a.put `rand()`:INTEGER to i;
};
bubble a;
a.foreach { item : INTEGER;
item.print;
'\n'.print;
};
);
- bubble a : ARRAY(INTEGER) <- (
+ lower, size, t : INTEGER;
+ sorted : BOOLEAN;
lower := a.lower;
size := a.upper - lower + 1;
{
sorted := TRUE;
size := size - 1;
0.to (size - 1) do { i : INTEGER;
(a.item(lower + i + 1) < a.item(lower + i)).if {
t := a.item(lower + i + 1);
a.put (a.item(lower + i)) to (lower + i + 1);
a.put t to (lower + i);
sorted := FALSE;
};
};
}.do_while {!sorted};
);</lang>
Lua
<lang Lua> function bubbleSort(A)
local itemCount=#A
local hasChanged
repeat
hasChanged = false
itemCount=itemCount - 1
for i = 1, itemCount do
if A[i] > A[i + 1] then
A[i], A[i + 1] = A[i + 1], A[i]
hasChanged = true
end
end
until hasChanged == false
end </lang>
Example: <lang lua> list = { 5, 6, 1, 2, 9, 14, 2, 15, 6, 7, 8, 97 } bubbleSort(list) for i, j in pairs(list) do
print(j)
end </lang>
Lucid
[1] <lang lucid>bsort(a) = if iseod(first a) then a else
follow(bsort(allbutlast(b)),last(b)) fi
where
b = bubble(a);
bubble(a) = smaller(max, next a)
where
max = first a fby larger(max, next a);
larger(x,y) = if iseod(y) then y elseif x
end;
follow(x,y) = if xdone then y upon xdone else x fi
where
xdone = iseod x fby xdone or iseod x;
end;
last(x) = (x asa iseod next x) fby eod;
allbutlast(x) = if not iseod(next x) then x else eod fi;
end</lang>
M4
<lang M4>divert(-1)
define(`randSeed',141592653) define(`setRand',
`define(`randSeed',ifelse(eval($1<10000),1,`eval(20000-$1)',`$1'))')
define(`rand_t',`eval(randSeed^(randSeed>>13))') define(`random',
`define(`randSeed',eval((rand_t^(rand_t<<18))&0x7fffffff))randSeed')
define(`set',`define(`$1[$2]',`$3')') define(`get',`defn(`$1[$2]')') define(`new',`set($1,size,0)') dnl for the heap calculations, it's easier if origin is 0, so set value first define(`append',
`set($1,size,incr(get($1,size)))`'set($1,get($1,size),$2)')
dnl swap(<name>,<j>,<name>[<j>],<k>) using arg stack for the temporary define(`swap',`set($1,$2,get($1,$4))`'set($1,$4,$3)')
define(`deck',
`new($1)for(`x',1,$2,
`append(`$1',eval(random%100))')')
define(`show',
`for(`x',1,get($1,size),`get($1,x) ')')
define(`for',
`ifelse($#,0,``$0, `ifelse(eval($2<=$3),1, `pushdef(`$1',$2)$4`'popdef(`$1')$0(`$1',incr($2),$3,`$4')')')')
define(`bubbleonce',
`for(`x',1,$2,
`ifelse(eval(get($1,x)>get($1,incr(x))),1,
`swap($1,x,get($1,x),incr(x))`'1')')0')
define(`bubbleupto',
`ifelse(bubbleonce($1,$2),0,
`',
`bubbleupto($1,decr($2))')')
define(`bubblesort',
`bubbleupto($1,decr(get($1,size)))')
divert deck(`a',10) show(`a') bubblesort(`a') show(`a')</lang>
- Output:
17 63 80 55 90 88 25 9 71 38 9 17 25 38 55 63 71 80 88 90
Mathematica / Wolfram Language
<lang Mathematica>bubbleSort[{w___, x_, y_, z___}] /; x > y := bubbleSort[{w, y, x, z}] bubbleSort[sortedList_] := sortedList</lang> Example:
bubbleSort[{10, 3, 7, 1, 4, 3, 8, 13, 9}]
{1, 3, 3, 4, 7, 8, 9, 10, 13}
MATLAB
<lang MATLAB>function list = bubbleSort(list)
hasChanged = true;
itemCount = numel(list);
while(hasChanged)
hasChanged = false;
itemCount = itemCount - 1;
for index = (1:itemCount)
if(list(index) > list(index+1))
list([index index+1]) = list([index+1 index]); %swap
hasChanged = true;
end %if
end %for
end %while
end %bubbleSort</lang>
- Output:
bubbleSort([5 3 8 4 9 7 6 2 1])
ans =
1 2 3 4 5 6 7 8 9
MAXScript
<lang maxscript>fn bubbleSort arr = (
while true do
(
changed = false
for i in 1 to (arr.count - 1) do
(
if arr[i] > arr[i+1] then
(
swap arr[i] arr[i+1]
changed = true
)
)
if not changed then exit
)
arr
)</lang>
-- Usage
<lang maxscript>myArr = #(9, 8, 7, 6, 5, 4, 3, 2, 1) myArr = bubbleSort myArr</lang>
MMIX
<lang mmix>Ja IS $127
LOC Data_Segment
DataSeg GREG @ Array IS @-Data_Segment
OCTA 999,200,125,1,1020,40,4,5,60,100
ArrayLen IS (@-Array-Data_Segment)/8
NL IS @-Data_Segment BYTE #a,0 LOC @+(8-@)&7
Buffer IS @-Data_Segment
LOC #1000
GREG @
sorted IS $5 i IS $6 size IS $1 a IS $0 t IS $20 t1 IS $21 t2 IS $22 % Input: $0 ptr to array, $1 its length (in octabyte) % Trashed: $5, $6, $1, $20, $21, $22 BubbleSort SETL sorted,1 % sorted = true
SUB size,size,1 % size--
SETL i,0 % i = 0
3H CMP t,i,size % i < size ?
BNN t,1F % if false, end for loop
8ADDU $12,i,a % compute addresses of the
ADDU t,i,1 % octas a[i] and a[i+1]
8ADDU $11,t,a
LDO t1,$12,0 % get their values
LDO t2,$11,0
CMP t,t1,t2 % compare
BN t,2F % if t1<t2, next
STO t1,$11,0 % else swap them
STO t2,$12,0
SETL sorted,0 % sorted = false
2H INCL i,1 % i++
JMP 3B % next (for loop)
1H PBZ sorted,BubbleSort % while sorted is false, loop
GO Ja,Ja,0
% Help function (Print an octabyte) % Input: $0 (the octabyte) BufSize IS 64
GREG @
PrintInt8 ADDU t,DataSeg,Buffer % get buffer address
ADDU t,t,BufSize % end of buffer
SETL t1,0 % final 0 for Fputs
STB t1,t,0
1H SUB t,t,1 % t--
DIV $0,$0,10 % ($0,rR) = divmod($0,10)
GET t1,rR % get reminder
INCL t1,'0' % turn it into ascii digit
STB t1,t,0 % store it
PBNZ $0,1B % if $0 /= 0, loop
OR $255,t,0 % $255 = t
TRAP 0,Fputs,StdOut
GO Ja,Ja,0 % print and return
Main ADDU $0,DataSeg,Array % $0 = Array address
SETL $1,ArrayLen % $1 = Array Len
GO Ja,BubbleSort % BubbleSort it
SETL $4,ArrayLen % $4 = ArrayLen
ADDU $3,DataSeg,Array % $3 = Array address 2H BZ $4,1F % if $4 == 0, break
LDO $0,$3,0 % $0 = * ($3 + 0)
GO Ja,PrintInt8 % print the octa
ADDU $255,DataSeg,NL % add a trailing newline
TRAP 0,Fputs,StdOut
ADDU $3,$3,8 % next octa
SUB $4,$4,1 % $4--
JMP 2B % loop 1H XOR $255,$255,$255
TRAP 0,Halt,0 % exit(0)</lang>
Modula-2
<lang modula2>PROCEDURE BubbleSort(VAR a: ARRAY OF INTEGER);
VAR changed: BOOLEAN; temp, count, i: INTEGER;
BEGIN
count := HIGH(a);
REPEAT
changed := FALSE;
DEC(count);
FOR i := 0 TO count DO
IF a[i] > a[i+1] THEN
temp := a[i];
a[i] := a[i+1];
a[i+1] := temp;
changed := TRUE
END
END
UNTIL NOT changed
END BubbleSort;</lang>
Modula-3
<lang modula3>MODULE Bubble;
PROCEDURE Sort(VAR a: ARRAY OF INTEGER) =
VAR sorted: BOOLEAN;
temp, len: INTEGER := LAST(a);
BEGIN
WHILE NOT sorted DO
sorted := TRUE;
DEC(len);
FOR i := FIRST(a) TO len DO
IF a[i+1] < a[i] THEN
temp := a[i];
a[i] := a[i + 1];
a[i + 1] := temp;
sorted := FALSE;
END;
END;
END;
END Sort;
END Bubble.</lang>
Nemerle
Functional
<lang Nemerle>using System; using System.Console;
module Bubblesort {
Bubblesort[T] (x : list[T]) : list[T]
where T : IComparable
{
def isSorted(y)
{
|[_] => true
|y1::y2::ys => (y1.CompareTo(y2) < 0) && isSorted(y2::ys)
}
def sort(y)
{
|[y] => [y]
|y1::y2::ys => if (y1.CompareTo(y2) < 0) y1::sort(y2::ys)
else y2::sort(y1::ys)
}
def loop(y)
{
if (isSorted(y)) y else {def z = sort(y); loop(z)}
}
match(x)
{
|[] => []
|_ => loop(x)
}
}
Main() : void
{
def empty = [];
def single = [2];
def several = [2, 6, 1, 7, 3, 9, 4];
WriteLine(Bubblesort(empty));
WriteLine(Bubblesort(single));
WriteLine(Bubblesort(several));
}
}</lang>
Imperative
We use an array for this version so that we can update in place. We could use a C# style list (as in the C# example), but that seemed too easy to confuse with a Nemerle style list. <lang Nemerle>using System; using System.Console;
module Bubblesort {
public static Bubblesort[T](this x : array[T]) : void
where T : IComparable
{
mutable changed = false;
def ln = x.Length;
do
{
changed = false;
foreach (i in [0 .. (ln - 2)])
{
when (x[i].CompareTo(x[i + 1]) > 0)
{
x[i] <-> x[i + 1];
changed = true;
}
}
} while (changed);
}
Main() : void
{
def several = array[2, 6, 1, 7, 3, 9, 4];
several.Bubblesort();
foreach (i in several)
Write($"$i ");
}
}</lang>
NetRexx
<lang NetRexx>/* NetRexx */ options replace format comments java crossref savelog symbols binary
placesList = [String -
"UK London", "US New York" - , "US Boston", "US Washington" - , "UK Washington", "US Birmingham" - , "UK Birmingham", "UK Boston" -
] sortedList = bubbleSort(String[] Arrays.copyOf(placesList, placesList.length))
lists = [placesList, sortedList] loop ln = 0 to lists.length - 1
cl = lists[ln] loop ct = 0 to cl.length - 1 say cl[ct] end ct say end ln
return
method bubbleSort(list = String[]) public constant binary returns String[]
listLen = list.length loop i_ = 0 to listLen - 1
loop j_ = i_ + 1 to listLen - 1
if list[i_].compareTo(list[j_]) > 0 then do
tmpstor = list[j_]
list[j_] = list[i_]
list[i_] = tmpstor
end
end j_
end i_
return list </lang>
- Output:
UK London US New York US Boston US Washington UK Washington US Birmingham UK Birmingham UK Boston UK Birmingham UK Boston UK London UK Washington US Birmingham US Boston US New York US Washington
Translation of Pseudocode
This version is a direct implementation of this task's pseudocode. <lang NetRexx>/* NetRexx */ options replace format comments java crossref savelog symbols binary
placesList = [String -
"UK London", "US New York" - , "US Boston", "US Washington" - , "UK Washington", "US Birmingham" - , "UK Birmingham", "UK Boston" -
] sortedList = bubbleSort(String[] Arrays.copyOf(placesList, placesList.length))
lists = [placesList, sortedList] loop ln = 0 to lists.length - 1
cl = lists[ln] loop ct = 0 to cl.length - 1 say cl[ct] end ct say end ln
return
method bubbleSort(item = String[]) public constant binary returns String[]
hasChanged = boolean itemCount = item.length loop label h_ until \hasChanged
hasChanged = isFalse
itemCount = itemCount - 1
loop index = 0 to itemCount - 1
if item[index].compareTo(item[index + 1]) > 0 then do
swap = item[index]
item[index] = item[index + 1]
item[index + 1] = swap
hasChanged = isTrue
end
end index
end h_
return item
method isTrue public constant binary returns boolean
return 1 == 1
method isFalse public constant binary returns boolean
return \isTrue
</lang>
Nim
<lang nim>proc bubbleSort[T](a: var openarray[T]) =
var t = true
for n in countdown(a.len-2, 0):
if not t: break
t = false
for j in 0..n:
if a[j] <= a[j+1]: continue
swap a[j], a[j+1]
t = true
var a = @[4, 65, 2, -31, 0, 99, 2, 83, 782] bubbleSort a echo a</lang>
- Output:
@[-31, 0, 2, 2, 4, 65, 83, 99, 782]
Objeck
<lang objeck> function : Swap(p : Int[]) ~ Nil {
t := p[0]; p[0] := p[1]; p[1] := t;
}
function : Sort(a : Int[]) ~ Nil {
do {
sorted := true;
size -= 1;
for (i:=0; i<a->Size(); i+=1;) {
if (a[i+1] < a[i]) {
swap(a+i);
sorted := 0;
};
};
}
while (sorted = false);
} </lang>
Objective-C
<lang objc>- (NSArray *) bubbleSort:(NSMutableArray *)unsorted {
BOOL done = false;
while (!done) {
done = true;
for (int i = 1; i < unsorted.count; i++) {
if ( [[unsorted objectAtIndex:i-1] integerValue] > [[unsorted objectAtIndex:i] integerValue] ) {
[unsorted exchangeObjectAtIndex:i withObjectAtIndex:i-1];
done = false;
}
}
}
return unsorted;
} </lang>
OCaml
Like the Haskell versions above:
This version checks for changes in a separate step for simplicity. <lang ocaml>let rec bsort s =
let rec _bsort = function
| x :: x2 :: xs when x > x2 ->
x2 :: _bsort (x :: xs)
| x :: x2 :: xs ->
x :: _bsort (x2 :: xs)
| s -> s
in
let t = _bsort s in
if t = s then t
else bsort t</lang>
This version uses the polymorphic option type to designate unchanged lists. (The type signature of _bsort is now 'a list -> 'a list option.) It is slightly faster than the previous one. <lang ocaml>let rec bsort s =
let rec _bsort = function
| x :: x2 :: xs when x > x2 -> begin
match _bsort (x :: xs) with
| None -> Some (x2 :: x :: xs)
| Some xs2 -> Some (x2 :: xs2)
end
| x :: x2 :: xs -> begin
match _bsort (x2 :: xs) with
| None -> None
| Some xs2 -> Some (x :: xs2)
end
| _ -> None
in
match _bsort s with
| None -> s
| Some s2 -> bsort s2</lang>
Octave
<lang octave>function s = bubblesort(v)
itemCount = length(v);
do
hasChanged = false;
itemCount--;
for i = 1:itemCount
if ( v(i) > v(i+1) )
v([i,i+1]) = v([i+1,i]); % swap hasChanged = true;
endif endfor until(hasChanged == false) s = v;
endfunction</lang>
<lang octave>v = [9,8,7,3,1,100]; disp(bubblesort(v));</lang>
ooRexx
Reimplementation of NetRexx
This version exploits the "Collection Classes" and some other features of the language that are only available in Open Object Rexx. <lang ooRexx>/* Rexx */ Do
placesList = sampleData() call show placesList say sortedList = bubbleSort(placesList) call show sortedList say
return
End Exit
-- ----------------------------------------------------------------------------- bubbleSort: procedure Do
il = arg(1) sl = il~copy
listLen = sl~size
loop i_ = 1 to listLen
loop j_ = i_ + 1 to listLen
cmpi = sl[i_]
cmpj = sl[j_]
if cmpi > cmpj then do
sl[i_] = cmpj
sl[j_] = cmpi
end
end j_
end i_
return sl
End Exit
-- ----------------------------------------------------------------------------- show: procedure Do
al = arg(1)
loop e_ over al say e_ end e_ return
End Exit
-- ----------------------------------------------------------------------------- sampleData: procedure Do
placesList = .array~of( , "UK London", "US New York", "US Boston", "US Washington", , "UK Washington", "US Birmingham", "UK Birmingham", "UK Boston" , )
return placesList
End Exit
</lang>
- Output:
UK London US New York US Boston US Washington UK Washington US Birmingham UK Birmingham UK Boston UK Birmingham UK Boston UK London UK Washington US Birmingham US Boston US New York US Washington
Translation of Pseudocode
This version is a direct implementation of this task's pseudocode. <lang ooRexx>/* Rexx */ Do
placesList = sampleData() call show placesList say sortedList = bubbleSort(placesList) call show sortedList say
return
End Exit
-- ----------------------------------------------------------------------------- bubbleSort: procedure Do
il = arg(1) sl = il~copy itemCount = sl~size
loop label c_ until \hasChanged
hasChanged = isFalse()
itemCount = itemCount - 1
loop i_ = 1 to itemCount
if sl[i_] > sl[i_ + 1] then do
t_ = sl[i_]
sl[i_] = sl[i_ + 1]
sl[i_ + 1] = t_
hasChanged = isTrue()
end
end i_
end c_
return sl
End Exit
-- ----------------------------------------------------------------------------- show: procedure Do
al = arg(1)
loop e_ over al say e_ end e_ return
End Exit
-- ----------------------------------------------------------------------------- sampleData: procedure Do
placesList = .array~of( , "UK London", "US New York", "US Boston", "US Washington", , "UK Washington", "US Birmingham", "UK Birmingham", "UK Boston" , )
return placesList
End Exit
-- ----------------------------------------------------------------------------- isTrue: procedure
return (1 == 1)
-- ----------------------------------------------------------------------------- isFalse: procedure
return \isTrue()
</lang>
Classic Rexx Implementation
A more "traditional" implementation of version 1 using only Rexx primitive constructs. This version has been tested with the Open Object Rexx and Regina Rexx interpreters and could equally have been exhibited as a Rexx solution. <lang ooRexx>/* Rexx */ Do
placesList. = sortedList. = call sampleData call bubbleSort
do i_ = 1 to placesList.0 say placesList.i_ end i_ say
do i_ = 1 to sortedList.0 say sortedList.i_ end i_ say
return
End Exit
/* -------------------------------------------------------------------------- */ bubbleSort: procedure expose sortedList. placesList. Do
/* Copy list */ do !_ = 0 to placesList.0 sortedList.!_ = placesList.!_ end !_
listLen = sortedList.0
do i_ = 1 to listLen
do j_ = i_ + 1 to listLen
if sortedList.i_ > sortedList.j_ then do
!_ = sortedList.j_
sortedList.j_ = sortedList.i_
sortedList.i_ = !_
end
end j_
end i_
return
End Exit
/* -------------------------------------------------------------------------- */ sampleData: procedure expose placesList. Do
! = 0 ! = ! + 1; placesList.0 = !; placesList.! = "UK London" ! = ! + 1; placesList.0 = !; placesList.! = "US New York" ! = ! + 1; placesList.0 = !; placesList.! = "US Boston" ! = ! + 1; placesList.0 = !; placesList.! = "US Washington" ! = ! + 1; placesList.0 = !; placesList.! = "UK Washington" ! = ! + 1; placesList.0 = !; placesList.! = "US Birmingham" ! = ! + 1; placesList.0 = !; placesList.! = "UK Birmingham" ! = ! + 1; placesList.0 = !; placesList.! = "UK Boston"
return
End Exit </lang>
Oz
In-place sorting of mutable arrays: <lang oz>declare
proc {BubbleSort Arr}
proc {Swap I J}
Arr.J := (Arr.I := Arr.J) %% assignment returns the old value
end
IsSorted = {NewCell false}
MaxItem = {NewCell {Array.high Arr}-1}
in
for until:@IsSorted do
IsSorted := true
for I in {Array.low Arr}..@MaxItem do
if Arr.I > Arr.(I+1) then
IsSorted := false
{Swap I I+1}
end
end
MaxItem := @MaxItem - 1
end
end
Arr = {Tuple.toArray unit(10 9 8 7 6 5 4 3 2 1)}
in
{BubbleSort Arr}
{Inspect Arr}</lang>
Purely-functional sorting of immutable lists: <lang oz>declare
local
fun {Loop Xs Changed ?IsSorted}
case Xs
of X1|X2|Xr andthen X1 > X2 then
X2|{Loop X1|Xr true IsSorted}
[] X|Xr then
X|{Loop Xr Changed IsSorted}
[] nil then
IsSorted = {Not Changed}
nil
end
end
in
fun {BubbleSort Xs}
IsSorted
Result = {Loop Xs false ?IsSorted}
in
if IsSorted then Result
else {BubbleSort Result}
end
end
end
in
{Show {BubbleSort [3 1 4 1 5 9 2 6 5]}}</lang>
PARI/GP
<lang parigp>bubbleSort(v)={
for(i=1,#v-1,
for(j=i+1,#v,
if(v[j]<v[i],
my(t=v[j]);
v[j]=v[i];
v[i]=t
)
)
);
v
};</lang>
Pascal
<lang pascal>procedure bubble_sort(var list: array of real); var
i, j, n: integer; t: real;
begin
n := length(list);
for i := n downto 2 do
for j := 0 to i - 1 do
if list[j] > list[j + 1] then
begin
t := list[j];
list[j] := list[j + 1];
list[j + 1] := t;
end;
end;</lang>
Usage:<lang pascal>var
list: array[0 .. 9] of real;
// ... bubble_sort(list);</lang>
Perl
<lang perl># Sorts an array in place sub bubble_sort {
for my $i (0 .. $#_){
for my $j ($i + 1 .. $#_){
$_[$j] < $_[$i] and @_[$i, $j] = @_[$j, $i];
}
}
}</lang>
Usage:
<lang perl>my @a = (39, 25, 30, 28, 36, 72, 98, 25, 43, 38); bubble_sort(@a);</lang>
Perl 6
<lang perl6>sub bubble_sort (@a is rw) {
for ^@a -> $i {
for $i ^..^ @a -> $j {
@a[$j] < @a[$i] and @a[$i, $j] = @a[$j, $i];
}
}
}</lang>
Phix
Copy of Euphoria <lang Phix>function bubble_sort(sequence s) object tmp integer changed
for j=length(s) to 1 by -1 do
changed = 0
for i=1 to j-1 do
if s[i]>s[i+1] then
{s[i],s[i+1],changed} = {s[i+1],s[i],1}
end if
end for
if changed=0 then exit end if
end for
return s
end function
constant s = {4, 15, "delta", 2, -31, 0, "alfa", 19, "gamma", 2, 13, "beta", 782, 1}
puts(1,"Before: ") ?s puts(1,"After: ") ?bubble_sort(s)</lang>
- Output:
Before: {4,15,"delta",2,-31,0,"alpha",19,"gamma",2,13,"beta",782,1}
After: {-31,0,1,2,2,4,13,15,19,782,"alpha","beta","delta","gamma"}
PHP
<lang php>function bubbleSort( array &$array ) { do { $swapped = false; for( $i = 0, $c = count( $array ) - 1; $i < $c; $i++ ) { if( $array[$i] > $array[$i + 1] ) { list( $array[$i + 1], $array[$i] ) = array( $array[$i], $array[$i + 1] ); $swapped = true; } } } while( $swapped ); }</lang>
PL/I
<lang pli>/* A primitive bubble sort */ bubble_sort: procedure (A);
declare A(*) fixed binary; declare temp fixed binary; declare i fixed binary, no_more_swaps bit (1) aligned;
do until (no_more_swaps);
no_more_swaps = true;
do i = lbound(A,1) to hbound(A,1)-1;
if A(i) > A(i+1) then
do; temp = A(i); A(i) = A(i+1); A(i+1) = temp;
no_more_swaps = false;
end;
end;
end;
end bubble_sort;</lang>
PicoLisp
<lang PicoLisp>(de bubbleSort (Lst)
(use Chg
(loop
(off Chg)
(for (L Lst (cdr L) (cdr L))
(when (> (car L) (cadr L))
(xchg L (cdr L))
(on Chg) ) )
(NIL Chg Lst) ) ) )</lang>
Pop11
<lang pop11>define bubble_sort(v); lvars n=length(v), done=false, i; while not(done) do
true -> done;
n - 1 -> n;
for i from 1 to n do
if v(i) > v(i+1) then
false -> done;
;;; Swap using multiple assignment
(v(i+1), v(i)) -> (v(i), v(i+1));
endif;
endfor;
endwhile; enddefine;
- Test it
vars ar = { 10 8 6 4 2 1 3 5 7 9}; bubble_sort(ar); ar =></lang>
PostScript
<lang PostScript> /bubblesort{ /x exch def /temp x x length 1 sub get def /i x length 1 sub def /j i 1 sub def
x length 1 sub{ i 1 sub{ x j 1 sub get x j get lt { /temp x j 1 sub get def x j 1 sub x j get put x j temp put }if /j j 1 sub def }repeat /i i 1 sub def /j i 1 sub def }repeat x pstack }def </lang>
PowerShell
<lang powershell>function bubblesort ($a) {
$l = $a.Length
$hasChanged = $true
while ($hasChanged) {
$hasChanged = $false
$l--
for ($i = 0; $i -lt $l; $i++) {
if ($a[$i] -gt $a[$i+1]) {
$a[$i], $a[$i+1] = $a[$i+1], $a[$i]
$hasChanged = $true
}
}
}
}</lang>
Prolog
It's surprisingly easy in Prolog while coding this sort, to accidentally create a sort that is similar, but not identical to the bubble sort algorithm. Some of these are easier and shorter to code and work as well if not better. Having said that, it's difficult to think of a reason to code the bubble sort these days except as an example of inefficiency. <lang prolog>%___________________________________________________________________________ % Bubble sort
bubble(0, Res, Res, sorted). bubble(Len, [A,B|T], Res, unsorted) :- A > B, !, bubble(Len,[B,A|T], Res, _). bubble(Len, [A|T], [A|Ts], Ch) :- L is Len-1, bubble(L, T, Ts, Ch).
bubblesort(In, Out) :- length(In, Len), bubblesort(Len, In, Out). bubblesort(0, In, In). bubblesort(Len, In, Out) :- bubble(Len, In, Bubbled, SortFlag), % bubble the list (SortFlag=sorted -> Out=Bubbled; % list is already sorted SegLen is Len - 1, % one fewer to process writef('bubbled=%w\n', [Bubbled]), % show progress bubblesort(SegLen, Bubbled, Out)).
test :- In = [8,9,1,3,4,2,6,5,4], writef(' input=%w\n', [In]), bubblesort(In, R), writef('-> %w\n', [R]).</lang> for example:
?- test. input=[8,9,1,3,4,2,6,5,4] bubbled=[8,1,3,4,2,6,5,4,9] bubbled=[1,3,4,2,6,5,4,8,9] bubbled=[1,3,2,4,5,4,6,8,9] bubbled=[1,2,3,4,4,5,6,8,9] -> [1,2,3,4,4,5,6,8,9] true.
Alternative version
Should be ISO (but tested only with GNU Prolog). Note: doesn't constuct list for each swap, only for each pass. <lang prolog>:- initialization(main).
bubble_sort(Xs,Res) :-
write(Xs), nl , bubble_pass(Xs,Ys,Changed) , ( Changed == true -> bubble_sort(Ys,Res) ; Res = Xs ) .
bubble_pass(Xs,Res,Changed) :-
Xs = [X|Ys], Ys = [Y|Zs]
, ( X > Y -> H = Y, T = [X|Zs], Changed = true
; H = X, T = Ys
)
, Res = [H|R], !, bubble_pass(T,R,Changed)
; Res = Xs
.
test([8,9,1,3,4,2,6,5,4]).
main :- test(T), bubble_sort(T,_), halt.</lang>
- Output:
[8,9,1,3,4,2,6,5,4] [8,1,3,4,2,6,5,4,9] [1,3,4,2,6,5,4,8,9] [1,3,2,4,5,4,6,8,9] [1,2,3,4,4,5,6,8,9]
PureBasic
<lang PureBasic>Procedure bubbleSort(Array a(1))
Protected i, itemCount, hasChanged
itemCount = ArraySize(a())
Repeat
hasChanged = #False
itemCount - 1
For i = 0 To itemCount
If a(i) > a(i + 1)
Swap a(i), a(i + 1)
hasChanged = #True
EndIf
Next
Until hasChanged = #False
EndProcedure</lang>
Python
<lang python>def bubble_sort(seq):
"""Inefficiently sort the mutable sequence (list) in place.
seq MUST BE A MUTABLE SEQUENCE.
As with list.sort() and random.shuffle this does NOT return
"""
changed = True
while changed:
changed = False
for i in xrange(len(seq) - 1):
if seq[i] > seq[i+1]:
seq[i], seq[i+1] = seq[i+1], seq[i]
changed = True
return None
if __name__ == "__main__":
"""Sample usage and simple test suite"""
from random import shuffle
testset = range(100) testcase = testset[:] # make a copy shuffle(testcase) assert testcase != testset # we've shuffled it bubble_sort(testcase) assert testcase == testset # we've unshuffled it back into a copy</lang>
Qi
<lang Qi>(define bubble-shot
[A] -> [A] [A B|R] -> [B|(bubble-shot [A|R])] where (> A B) [A |R] -> [A|(bubble-shot R)])
(define bubble-sort
X -> (fix bubble-shot X))
(bubble-sort [6 8 5 9 3 2 2 1 4 7]) </lang>
R
<lang R>bubblesort <- function(v) {
itemCount <- length(v)
repeat {
hasChanged <- FALSE
itemCount <- itemCount - 1
for(i in 1:itemCount) {
if ( v[i] > v[i+1] ) {
t <- v[i]
v[i] <- v[i+1]
v[i+1] <- t
hasChanged <- TRUE
}
}
if ( !hasChanged ) break;
}
v
}
v <- c(9,8,7,3,1,100) print(bubblesort(v))</lang>
Ra
<lang Ra> class BubbleSort **Sort a list with the Bubble Sort algorithm**
on start
args := program arguments .sort(args) print args
define sort(list) is shared **Sort the list**
test list := [4, 2, 7, 3] .sort(list) assert list = [2, 3, 4, 7]
body last := list.count - 1
post while changed
changed := false
for i in last
if list[i] > list[i + 1] temp := list[i] list[i] := list[i + 1] list[i + 1] := temp changed := true </lang>
Racket
This bubble sort sorts the elelement in the vector v with regard to <?.
<lang racket>
- lang racket
(define (bubble-sort <? v)
(define len (vector-length v))
(define ref vector-ref)
(let loop ([max len]
[again? #f])
(for ([i (in-range 0 (- max 1))]
[j (in-range 1 max)])
(define vi (ref v i))
(when (<? (ref v j) vi)
(vector-set! v i (ref v j))
(vector-set! v j vi)
(set! again? #t)))
(when again? (loop (- max 1) #f)))
v)
</lang>
Example: Sorting a vector of length 10 with random entries. <lang racket> (bubble-sort < (for/vector ([_ 10]) (random 20))) </lang>
REALbasic
Sorts an array of Integers
<lang vb>
Dim sortable() As Integer ' assume the array is populated sortable.Shuffle() ' sortable is now randomized Dim swapped As Boolean Do Dim index, bound As Integer bound = sortable.Ubound
While index < bound
If Sortable(index) > Sortable(index + 1) Then
Dim s As Integer = Sortable(index)
Sortable.Remove(index)
Sortable.Insert(index + 1, s)
swapped = True
End If
index = index + 1
Wend
Loop Until Not swapped
'sortable is now sorted </lang>
REXX
<lang rexx>/*REXX program sorts an array (of any items) using the bubble-sort algorithm.*/ call gen /*generate the array elements (items).*/ call show 'before sort' /*show the before array elements. */
say copies('─',79) /*show a separator line (before/after).*/
call bubbleSort # /*invoke the bubble sort with # items.*/ call show ' after sort' /*show the after array elements. */ exit /*stick a fork in it, we're all done. */ /*────────────────────────────────────────────────────────────────────────────*/ bubbleSort: procedure expose @.; parse arg n /*N: number of array elements.*/ m=n-1 /*use this as a handy variable for sort*/
do until done; done=1 /*keep sorting the array until done. */
do j=1 for m; k=j+1 /*search for an element out─of─order. */
if @.j>@.k then do; _=@.j /*Out of order? Then swap two elements*/
@.j=@.k /*swap current element with the next···*/
@.k=_ /* ··· and the next with _ */
done=0 /*indicate that the sorting isn't done,*/
end /* (1≡true, 0≡false). */
end /*j*/
end /*until ··· */
return /*────────────────────────────────────────────────────────────────────────────*/ gen: @. = /*assign a default value to all of @. */
@.1 = '---letters of the Hebrew alphabet---' ; @.13 = 'kaph [kaf]'
@.2 = '====================================' ; @.14 = 'lamed'
@.3 = 'aleph [alef]' ; @.15 = 'mem'
@.4 = 'beth [bet]' ; @.16 = 'nun'
@.5 = 'gimel' ; @.17 = 'samekh'
@.6 = 'daleth [dalet]' ; @.18 = 'ayin'
@.7 = 'he' ; @.19 = 'pe'
@.8 = 'waw [vav]' ; @.20 = 'sadhe [tsadi]'
@.9 = 'zayin' ; @.21 = 'qoph [qof]'
@.10 = 'heth [het]' ; @.22 = 'resh'
@.11 = 'teth [tet]' ; @.23 = 'shin'
@.12 = 'yod' ; @.24 = 'taw [tav]'
do #=1 while @.#\==; end; #=#-1 /*find how many elements in list.*/
w=length(#) /*the maximum width of any index.*/
return
/*────────────────────────────────────────────────────────────────────────────*/ show: do j=1 for #; say 'element' right(j,w) arg(1)":" @.j; end; return</lang> output when using the internal array list:
element 1 before sort: ---letters of the Hebrew alphabet--- element 2 before sort: ==================================== element 3 before sort: aleph [alef] element 4 before sort: beth [bet] element 5 before sort: gimel element 6 before sort: daleth [dalet] element 7 before sort: he element 8 before sort: waw [vav] element 9 before sort: zayin element 10 before sort: heth [het] element 11 before sort: teth [tet] element 12 before sort: yod element 13 before sort: kaph [kaf] element 14 before sort: lamed element 15 before sort: mem element 16 before sort: nun element 17 before sort: samekh element 18 before sort: ayin element 19 before sort: pe element 20 before sort: sadhe [tsadi] element 21 before sort: qoph [qof] element 22 before sort: resh element 23 before sort: shin element 24 before sort: taw [tav] ─────────────────────────────────────────────────────────────────────────────── element 1 after sort: ---letters of the Hebrew alphabet--- element 2 after sort: ==================================== element 3 after sort: aleph [alef] element 4 after sort: ayin element 5 after sort: beth [bet] element 6 after sort: daleth [dalet] element 7 after sort: gimel element 8 after sort: he element 9 after sort: heth [het] element 10 after sort: kaph [kaf] element 11 after sort: lamed element 12 after sort: mem element 13 after sort: nun element 14 after sort: pe element 15 after sort: qoph [qof] element 16 after sort: resh element 17 after sort: sadhe [tsadi] element 18 after sort: samekh element 19 after sort: shin element 20 after sort: taw [tav] element 21 after sort: teth [tet] element 22 after sort: waw [vav] element 23 after sort: yod element 24 after sort: zayin
Ring
<lang ring>bubbleList = [4,2,1,3] flag = 0 bubbleSort(bubbleList) see bubbleList
func bubbleSort A
n = len(A)
while flag = 0
flag = 1
for i = 1 to n-1
if A[i] > A[i+1]
temp = A[i]
A[i] = A[i+1]
A[i+1] = temp
flag = 0
ok
next
end
</lang>
Ruby
This example adds the bubblesort! method to the Array object. Below are two different methods that show four different iterating constructs in ruby.
<lang ruby>class Array
def bubblesort1!
length.times do |j|
for i in 1...(length - j)
if self[i] < self[i - 1]
self[i], self[i - 1] = self[i - 1], self[i]
end
end
end
self
end
def bubblesort2!
each_index do |index|
(length - 1).downto( index ) do |i|
self[i-1], self[i] = self[i], self[i-1] if self[i-1] < self[i]
end
end
self
end
end ary = [3, 78, 4, 23, 6, 8, 6] ary.bubblesort1! p ary
- => [3, 4, 6, 6, 8, 23, 78]</lang>
Run BASIC
<lang runbasic>siz = 100 dim data$(siz) unSorted = 1
WHILE unSorted
unSorted = 0
FOR i = 1 TO siz -1
IF data$(i) > data$(i + 1) THEN
tmp = data$(i)
data$(i) = data$(i + 1)
data$(i + 1) = tmp
unSorted = 1
END IF
NEXT
WEND</lang>
Rust
<lang rust>fn bubble_sort<T: Ord>(values: &mut[T]) {
let mut n = values.len(); let mut swapped = true;
while swapped {
swapped = false;
for i in 1..n {
if values[i - 1] > values[i] {
values.swap(i - 1, i);
swapped = true;
}
}
n = n - 1; }
}
fn main() {
// Sort numbers.
let mut numbers = [8, 7, 1, 2, 9, 3, 4, 5, 0, 6];
println!("Before: {:?}", numbers);
bubble_sort(&mut numbers);
println!("After: {:?}", numbers);
// Sort strings.
let mut strings = ["empty", "beach", "art", "car", "deal"];
println!("Before: {:?}", strings);
bubble_sort(&mut strings);
println!("After: {:?}", strings);
}</lang>
Sather
<lang sather>class SORT{T < $IS_LT{T}} is
private swap(inout a, inout b:T) is
temp ::= a;
a := b;
b := temp;
end;
bubble_sort(inout a:ARRAY{T}) is
i:INT;
if a.size < 2 then return; end;
loop
sorted ::= true;
loop i := 0.upto!(a.size - 2);
if a[i+1] < a[i] then
swap(inout a[i+1], inout a[i]);
sorted := false;
end;
end;
until!(sorted);
end;
end;
end;</lang>
<lang sather>class MAIN is
main is
a:ARRAY{INT} := |10, 9, 8, 7, 6, -10, 5, 4|;
SORT{INT}::bubble_sort(inout a);
#OUT + a + "\n";
end;
end;</lang>
This should be able to sort (in ascending order) any object for which is_lt (less than) is defined.
Scala
This slightly more complex version of Bubble Sort avoids errors with indices.
<lang scala>def bubbleSort[T](arr: Array[T])(implicit o: Ordering[T]) {
import o._
val consecutiveIndices = (arr.indices, arr.indices drop 1).zipped
var hasChanged = true
do {
hasChanged = false
consecutiveIndices foreach { (i1, i2) =>
if (arr(i1) > arr(i2)) {
hasChanged = true
val tmp = arr(i1)
arr(i1) = arr(i2)
arr(i2) = tmp
}
}
} while(hasChanged)
}</lang>
<lang scala>import scala.annotation.tailrec
def bubbleSort(xt: List[Int]) = {
@tailrec
def bubble(xs: List[Int], rest: List[Int], sorted: List[Int]): List[Int] = xs match {
case x :: Nil =>
if (rest.isEmpty) x :: sorted
else bubble(rest, Nil, x :: sorted)
case a :: b :: xs =>
if (a > b) bubble(a :: xs, b :: rest, sorted)
else bubble(b :: xs, a :: rest, sorted)
}
bubble(xt, Nil, Nil)
}</lang>
Scheme
<lang scheme>(define (bubble-sort x gt?)
(letrec
((fix (lambda (f i)
(if (equal? i (f i))
i
(fix f (f i)))))
(sort-step (lambda (l)
(if (or (null? l) (null? (cdr l)))
l
(if (gt? (car l) (cadr l))
(cons (cadr l) (sort-step (cons (car l) (cddr l))))
(cons (car l) (sort-step (cdr l))))))))
(fix sort-step x)))</lang>
This solution recursively finds the fixed point of sort-step. A comparison function must be passed to bubblesort. Example usages: <lang scheme>(bubble-sort (list 1 3 5 9 8 6 4 2) >) (bubble-sort (string->list "Monkey") char<?)</lang>
Here is the same function, using a different syntax:
<lang scheme>(define (bsort l gt?)
(define (dosort l)
(cond ((null? (cdr l))
l)
((gt? (car l) (cadr l))
(cons (cadr l) (dosort (cons (car l) (cddr l)))))
(else
(cons (car l) (dosort (cdr l))))))
(let ((try (dosort l)))
(if (equal? l try)
l
(bsort try gt?))))
</lang> For example, you could do <lang scheme>(bsort > '(2 4 6 2)) (1 2 3)</lang>
Scilab
<lang>function b=BubbleSort(a)
n=length(a)
swapped=%T
while swapped
swapped=%F
for i=1:1:n-1
if a(i)>a(i+1) then
temp=a(i)
a(i)=a(i+1)
a(i+1)=temp
swapped=%T
end
end
end
b=a
endfunction BubbleSort</lang>
- Output:
-->y=[5 4 3 2 1]
y =
5. 4. 3. 2. 1.
-->x=BubbleSort(a)
x =
1. 2. 3. 4. 5.
Scratch
This solution is hosted at the Scratch site, because it is difficult to document visual programming solutions directly here at Rosetta Code. There you can see the solution results as well as examine the code. This solution is intended to illustrate the Bubble sort algorithm rather than to maximize performance. Scratch provides visual queues to indicate list access, and these are used to help show what is happening.
Seed7
<lang seed7>const proc: bubbleSort (inout array elemType: arr) is func
local
var boolean: swapped is FALSE;
var integer: i is 0;
var elemType: help is elemType.value;
begin
repeat
swapped := FALSE;
for i range 1 to length(arr) - 1 do
if arr[i] > arr[i + 1] then
help := arr[i];
arr[i] := arr[i + 1];
arr[i + 1] := help;
swapped := TRUE;
end if;
end for;
until not swapped;
end func;</lang>
Original source: [2]
Sidef
<lang ruby>func bubble_sort(arr) {
loop {
var swapped = false;
{ |i|
arr[i-1] > arr[i] && (
arr[i-1, i] = arr[i, i-1];
swapped = true;
);
} * arr.end;
swapped || break;
}
return arr;
}</lang>
Smalltalk
A straight translation from the pseudocode above. Swap is done with a block closure.
<lang smalltalk>|item swap itemCount hasChanged| item := #(1 4 5 6 10 8 7 61 0 -3) copy. swap := [:indexOne :indexTwo| |temp| temp := item at: indexOne. item at: indexOne put: (item at: indexTwo). item at: indexTwo put: temp].
itemCount := item size. [hasChanged := false. itemCount := itemCount - 1. 1 to: itemCount do: [:index | (item at: index) > (item at: index + 1) ifTrue: [swap value: index value: index + 1. hasChanged := true]]. hasChanged] whileTrue.</lang>
SNOBOL4
<lang SNOBOL4>* # Sort array in place, return array
define('bubble(a,alen)i,j,ub,tmp') :(bubble_end)
bubble i = 1; ub = alen outer gt(ub,1) :f(bdone)
j = 1
inner le(a<j>, a<j + 1>) :s(incrj)
tmp = a<j>
a<j> = a<j + 1>
a<j + 1> = tmp
incrj j = lt(j + 1,ub) j + 1 :s(inner)
ub = ub - 1 :(outer)
bdone bubble = a :(return) bubble_end
- # Fill array with test data
str = '33 99 15 54 1 20 88 47 68 72'
output = str; arr = array(10)
floop i = i + 1; str span('0123456789') . arr = :s(floop)
- # Test and display
bubble(arr,10); str =
sloop j = j + 1; str = str arr<j> ' ' :s(sloop)
output = trim(str)
end</lang>
- Output:
33 99 15 54 1 20 88 47 68 72 1 15 20 33 47 54 68 72 88 99
SPARK
The first version is based on the Ada version, with Integer for both the array index and the array element.
Static analysis of this code shows that it is guaranteed free of any run-time error when called from any other SPARK code. <lang Ada>package Bubble is
type Arr is array(Integer range <>) of Integer;
procedure Sort (A : in out Arr); --# derives A from *;
end Bubble;
package body Bubble
is
procedure Sort (A : in out Arr)
is
Finished : Boolean;
Temp : Integer;
begin
if A'Last /= A'First then
loop
Finished := True;
for J in Integer range A'First .. A'Last - 1 loop
if A (J + 1) < A (J) then
Finished := False;
Temp := A (J + 1);
A (J + 1) := A (J);
A (J) := Temp;
end if;
end loop;
--# assert A'Last /= A'First;
exit when Finished;
end loop;
end if;
end Sort;
end Bubble; </lang> The next version has a postcondition to guarantee that the returned array is sorted correctly. This requires the two proof rules that follow the source. The Ada code is identical with the first version. <lang Ada>package Bubble is
type Arr is array(Integer range <>) of Integer;
-- Sorted is a proof function with the definition: -- Sorted(A, From_I, To_I) -- <-> -- (for all I in Integer range From_I .. To_I - 1 => -- (A(I) <= A(I + 1))) . -- --# function Sorted (A : Arr; --# From_I, To_I : Integer) return Boolean; procedure Sort (A : in out Arr); --# derives A from *; --# post Sorted(A, A'First, A'Last);
end Bubble;
package body Bubble
is
procedure Sort (A : in out Arr)
is
Finished : Boolean;
Temp : Integer;
begin
if A'Last > A'First then
loop
Finished := True;
for J in Integer range A'First .. A'Last - 1
--# assert Finished -> Sorted(A, A'First, J);
loop
if A (J + 1) < A (J) then
Finished := False;
Temp := A (J + 1);
A (J + 1) := A (J);
A (J) := Temp;
end if;
end loop;
--# assert A'Last /= A'First
--# and (Finished -> Sorted(A, A'First, A'Last));
exit when Finished;
end loop;
end if;
end Sort;
end Bubble; </lang> The proof rules are stated here without justification (but they are fairly obvious). A formal proof of these rules from the definition of Sorted has been completed.
bubble_sort_rule(1): sorted(A, I, J)
may_be_deduced_from
[ J <= I ] .
bubble_sort_rule(2): Fin -> sorted(A, I, J + 1)
may_be_deduced_from
[ Fin -> sorted(A, I, J),
element(A, [J]) <= element(A, [J + 1]) ] .
Both of the two versions above use an inner loop that scans over all the array on every pass of the outer loop. This makes the proof in the second version very simple.
The final version scans over a reducing portion of the array in the inner loop, consequently the proof becomes more complex. The package specification for this version is the same as the second version above. The package body defines two more proof functions. <lang Ada>package body Bubble is
procedure Sort (A : in out Arr)
is
Finished : Boolean;
-- In_Position is a proof function with the definition:
-- In_Position(A, A_Start, A_I, A_End)
-- <->
-- ((for all K in Integer range A_Start .. A_I - 1 =>
-- (A(K) <= A(A_I)))
-- and
-- Sorted(A, A_I, A_End) .
--
--# function In_Position (A : Arr;
--# A_Start, A_I, A_End : Integer) return Boolean;
-- Swapped is a proof function with the definition:
-- Swapped(A_In, A_Out, I1, I2)
-- <->
-- (A_Out = A_In[I1 => A_In(I2); I2 => A_In(I1)]).
--
--# function Swapped (A_In, A_Out : Arr;
--# I1, I2 : Integer) return Boolean;
procedure Swap (A : in out Arr;
I1 : in Integer;
I2 : in Integer)
--# derives A from *, I1, I2;
--# pre I1 in A'First .. A'Last
--# and I2 in A'First .. A'Last;
--# post Swapped(A~, A, I1, I2);
is
Temp : Integer;
begin
Temp := A(I2);
A(I2) := A(I1);
A(I1) := Temp;
end Swap;
pragma Inline (Swap);
begin
if A'Last > A'First then
for I in reverse Integer range A'First + 1 .. A'Last loop
Finished := True;
for J in Integer range A'First .. I - 1 loop
if A (J + 1) < A (J) then
Finished := False;
Swap (A, J, J + 1);
end if;
--# assert I% = I -- I is unchanged by execution of the loop
--# and (for all K in Integer range A'First .. J =>
--# (A(K) <= A(J + 1)))
--# and (I < A'Last -> In_Position(A, A'First, I + 1, A'Last))
--# and (Finished -> Sorted(A, A'First, J + 1));
end loop;
exit when Finished;
--# assert In_Position(A, A'First, I, A'Last);
end loop;
end if;
end Sort;
end Bubble; </lang> Completion of the proof of this version requires more rules than the previous version and they are rather more complex. Creation of these rules is quite straightforward - I tend to write whatever rules the Simplifier needs first and then validate them afterwards. A formal proof of these rules from the definition of Sorted, In_Position and Swapped has been completed.
bubble_sort_rule(1): sorted(A, I, J)
may_be_deduced_from
[ J <= I ] .
bubble_sort_rule(2): sorted(A, I - 1, J)
may_be_deduced_from
[ sorted(A, I, J),
element(A, [I - 1]) <= element(A, [I]) ] .
bubble_sort_rule(3): Fin -> sorted(A, I, J + 1)
may_be_deduced_from
[ Fin -> sorted(A, I, J),
element(A, [J]) <= element(A, [J + 1]) ] .
bubble_sort_rule(4): sorted(A, Fst, Lst)
may_be_deduced_from
[ sorted(A, Fst, I),
I < Lst -> in_position(A, Fst, I + 1, Lst),
I <= Lst ] .
bubble_sort_rule(5): in_position(A, Fst, I, Lst)
may_be_deduced_from
[ I < Lst -> in_position(A, Fst, I + 1, Lst),
for_all(K : integer, Fst <= K and K <= I - 1
-> element(A, [K]) <= element(A, [I])),
I >= Fst,
I <= Lst ] .
bubble_sort_rule(6): I < Lst -> in_position(A2, Fst, I + 1, Lst)
may_be_deduced_from
[ I < Lst -> in_position(A1, Fst, I + 1, Lst),
swapped(A1, A2, J + 1, J + 2),
J + 2 < I + 1,
J >= Fst ] .
bubble_sort_rule(7): I - 1 < Lst -> in_position(A2, Fst, I, Lst)
may_be_deduced_from
[ in_position(A1, Fst, I, Lst),
swapped(A1, A2, J, J + 1),
J + 1 < I,
J >= Fst ] .
bubble_sort_rule(8): for_all(K : integer, I <= K and K <= I
-> element(A, [K]) <= element(A, [I + 1]))
may_be_deduced_from
[ element(A, [I]) <= element(A, [I + 1]) ] .
bubble_sort_rule(9): for_all(K : integer, I <= K and K <= I
-> element(A2, [K]) <= element(A2, [I + 1]))
may_be_deduced_from
[ element(A1, [I]) > element(A1, [I + 1]),
swapped(A1, A2, I, I + 1) ] .
bubble_sort_rule(10): for_all(K2 : integer, Fst <= K2 and K2 <= J + 1
-> element(A, [K2]) <= element(A, [J + 2]))
may_be_deduced_from
[ for_all(K1 : integer, Fst <= K1 and K1 <= J
-> element(A, [K1]) <= element(A, [J + 1])),
element(A, [J + 1]) <= element(A, [J + 2]) ] .
bubble_sort_rule(11): for_all(K2 : integer, Fst <= K2 and K2 <= J + 1
-> element(A2, [K2]) <= element(A2, [J + 2]))
may_be_deduced_from
[ for_all(K1 : integer, Fst <= K1 and K1 <= J
-> element(A1, [K1]) <= element(A1, [J + 1])),
element(A1, [J + 1]) > element(A1, [J + 2]),
swapped(A1, A2, J + 1, J + 2) ] .
Standard ML
Assumes a list of integers.
fun bubble_select [] = []
| bubble_select [a] = [a]
| bubble_select (a::b::xs) =
if b < a then b::(bubble_select(a::xs)) else a::(bubble_select(b::xs))
fun bubblesort [] = []
| bubblesort (x::xs) =bubble_select (x::(bubblesort xs))
Swift
<lang Swift>func bubbleSort<T:Comparable>(inout list:[T]) {
var done = false
while !done {
done = true
for i in 1..<list.count {
if list[i - 1] > list[i] {
(list[i], list[i - 1]) = (list[i - 1], list[i])
done = false
}
}
}
}</lang>
TI-83 BASIC
Input your data into L1 and run this program to organize it.
:L1→L2 :1+dim(L2)→N :For(D,1,dim(L2)) :N-1→N :0→I :For(C,1,dim(L2)-2) :For(A,dim(L2)-N+1,dim(L2)-1) :If L2(A)>L2(A+1) :Then :1→I :L2(A)→B :L2(A+1)→L2(A) :B→L2(A+1) :End :End :End :If I=0 :Goto C :End :Lbl C :If L2(1)>L2(2) :Then :L2(1)→B :L2(2)→L2(1) :B→L2(2) :End :DelVar A :DelVar B :DelVar C :DelVar D :DelVar N :DelVar I :Return
Odd-Even Bubble Sort (same IO):
:"ODD-EVEN" :L1→L2( :1+dim(L2)→N :For(D,1,dim(L2)) :N-1→N :0→O :For(C,1,dim(L2)-2) :For(A,dim(L2)-N+2,dim(L2)-1,2) :If L2(A)>L2(A+1) :Then :1→O :L2(A)→B :L2(A+1)→L2(A) :B→L2(A+1) :End :End :For(A,dim(L2)-N+1,dim(L2)-1,2) :If L2(A)>L2(A+1) :Then :1→O :L2(A)→B :L2(A+1)→L2(A) :B→L2(A+1) :End :End :End :If O=0 :Goto C :End :Lbl C :If L2(1)>L2(2) :Then :L2(1)→B :L2(2)→L2(1) :B→L2(2) :End :DelVar A :DelVar B :DelVar C :DelVar D :DelVar N :DelVar O :Return
Implementation of the pseudo code given at the top of the page. Place data to be sorted in L1
:dim(L1)→D
:Repeat C=0
:0→C
:D–1→D
:For(I,1,D)
:If L1(I)>L1(I+1):Then
:L1(I)→C
:L1(I+1)→L1(I)
:C→L1(I+1)
:1→C
:End
:End
:End
:L1
Tcl
<lang tcl>package require Tcl 8.5 package require struct::list
proc bubblesort {A} {
set len [llength $A]
set swapped true
while {$swapped} {
set swapped false
for {set i 0} {$i < $len - 1} {incr i} {
set j [expr {$i + 1}]
if {[lindex $A $i] > [lindex $A $j]} {
struct::list swap A $i $j
set swapped true
}
}
incr len -1
}
return $A
}
puts [bubblesort {8 6 4 2 1 3 5 7 9}] ;# => 1 2 3 4 5 6 7 8 9</lang>
Idiomatic code uses the builtin lsort instead, which is a stable O(n log n) sort.
Toka
Toka does not have a bubble sort predefined, but it is easy to code a simple one:
<lang toka>#! A simple Bubble Sort function value| array count changed | [ ( address count -- )
to count to array
count 0
[ count 0
[ i array array.get i 1 + array array.get 2dup >
[ i array array.put i 1 + array array.put ]
[ 2drop ] ifTrueFalse
] countedLoop
count 1 - to count
] countedLoop
] is bsort
- ! Code to display an array
[ ( array count -- )
0 swap [ dup i swap array.get . ] countedLoop drop cr
] is .array
- ! Create a 10-cell array
10 cells is-array foo
- ! Fill it with random values
20 1 foo array.put 50 2 foo array.put 650 3 foo array.put 120 4 foo array.put 110 5 foo array.put 101 6 foo array.put
1321 7 foo array.put 1310 8 foo array.put
987 9 foo array.put 10 10 foo array.put
- ! Display the array, sort it, and display it again
foo 10 .array foo 10 bsort foo 10 .array</lang>
TorqueScript
<lang TorqueScript>//Note that we're assuming that the list of numbers is separated by tabs. function bubbleSort(%list) { %ct = getFieldCount(%list); for(%i = 0; %i < %ct; %i++) { for(%k = 0; %k < (%ct - %i - 1); %k++) { if(getField(%list, %k) > getField(%list, %k+1)) { %tmp = getField(%list, %k); %list = setField(%list, %k, getField(%list, %k+1)); %list = setField(%list, %k+1, %tmp); } } } return %list; }</lang>
uBasic/4tH
<lang>PRINT "Bubble sort:"
n = FUNC (_InitArray) PROC _ShowArray (n) PROC _Bubblesort (n) PROC _ShowArray (n)
END
_Bubblesort PARAM(1) ' Bubble sort
LOCAL (2)
DO
b@ = 0
FOR c@ = 1 TO a@-1
IF @(c@-1) > @(c@) THEN PROC _Swap (c@, c@-1) : b@ = c@
NEXT
a@ = b@
UNTIL b@ = 0
LOOP
RETURN
_Swap PARAM(2) ' Swap two array elements
PUSH @(a@) @(a@) = @(b@) @(b@) = POP()
RETURN
_InitArray ' Init example array
PUSH 4, 65, 2, -31, 0, 99, 2, 83, 782, 1 FOR i = 0 TO 9 @(i) = POP() NEXT
RETURN (i)
_ShowArray PARAM (1) ' Show array subroutine
FOR i = 0 TO a@-1 PRINT @(i), NEXT PRINT
RETURN</lang>
Unicon
See Icon.
UnixPipes
<lang bash>rm -f _sortpass
reset() {
test -f _tosort || mv _sortpass _tosort
}
bpass() {
(read a; read b
test -n "$b" -a "$a" && (
test $a -gt $b && (reset; echo $b; (echo $a ; cat) | bpass ) || (echo $a; (echo $b ; cat) | bpass )
) || echo $a)
}
bubblesort() {
cat > _tosort
while test -f _tosort
do
cat _tosort | (rm _tosort;cat) |bpass > _sortpass
done
cat _sortpass
}
cat to.sort | bubblesort</lang>
Ursala
The bubblesort function is parameterized by a relational predicate. <lang Ursala>#import nat
bubblesort "p" = @iNX ^=T ^llPrEZryPrzPlrPCXlQ/~& @l ~&aitB^?\~&a "p"?ahthPX/~&ahPfatPRC ~&ath2fahttPCPRC
- cast %nL
example = bubblesort(nleq) <362,212,449,270,677,247,567,532,140,315></lang>
- Output:
<140,212,247,270,315,362,449,532,567,677>
VBScript
Doing the decr and incr thing is superfluous, really. I just had stumbled over the byref thing for swap and wanted to see where else it would work.
For those unfamiliar with Perth, WA Australia, the five strings being sorted are names of highways.
Implementation
<lang vb> sub decr( byref n ) n = n - 1 end sub
sub incr( byref n ) n = n + 1 end sub
sub swap( byref a, byref b) dim tmp tmp = a a = b b = tmp end sub
function bubbleSort( a ) dim changed dim itemCount itemCount = ubound(a) do changed = false decr itemCount for i = 0 to itemCount if a(i) > a(i+1) then swap a(i), a(i+1) changed = true end if next loop until not changed bubbleSort = a end function </lang>
Invocation
<lang vb> dim a a = array( "great eastern", "roe", "stirling", "albany", "leach") wscript.echo join(a,", ") bubbleSort a wscript.echo join(a,", ") </lang>
- Output:
great eastern, roe, stirling, albany, leach albany, great eastern, leach, roe, stirling
Visual Basic .NET
Platform: .NET
<lang vbnet>Do Until NoMoreSwaps = True
NoMoreSwaps = True
For Counter = 1 To (NumberOfItems - 1)
If List(Counter) > List(Counter + 1) Then
NoMoreSwaps = False
Temp = List(Counter)
List(Counter) = List(Counter + 1)
List(Counter + 1) = Temp
End If
Next
NumberOfItems = NumberOfItems - 1
Loop</lang>
X86 Assembly
Translation of XPL0. Assemble with tasm, tlink /t <lang asm> .model tiny
.code
.486
org 100h
start: mov si, offset array
mov ax, 40 ;length of array (not including $)
call bsort
mov dx, si ;point to array
mov ah, 09h ;display it as a string
int 21h
ret
array db "Pack my box with five dozen liquor jugs.$"
- Bubble sort
- si = array addrsss, ax = number of bytes
bsort: pusha
xchg cx, ax ;get size of array N
dec cx ;for J:= N-1 downto 0
bs10: xor bx, bx ;for I:= 0 to J-1 bs20: mov ax, [bx+si]
cmp al, ah ;if A(I) > A(I+1) then
jbe bs30
xchg al, ah ; swap bytes
mov [bx+si], ax
bs30: inc bx ;next I
cmp bx, cx
jb bs20
loop bs10
popa
ret
end start</lang>
- Output:
.Pabcdeefghiiijklmnoooqrstuuvwxyz
XPL0
<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations string 0; \use zero-terminated strings
proc BSort(A, N); \Bubble sort array in ascending order char A; \address of array int N; \number of items in array (size) int I, J, T; [for J:= N-1 downto 0 do
for I:= 0 to J-1 do
if A(I) > A(I+1) then
[T:= A(I); A(I):= A(I+1); A(I+1):= T]; \swap items
]; \BSort
func StrLen(Str); \Return number of characters in an ASCIIZ string char Str; int I; for I:= 0 to -1>>1-1 do
if Str(I) = 0 then return I;
char Str; [Str:= "Pack my box with five dozen liquor jugs."; BSort(Str, StrLen(Str)); Text(0, Str); CrLf(0); ]</lang>
- Output:
" .Pabcdeefghiiijklmnoooqrstuuvwxyz"
Yorick
<lang yorick>func bubblesort(&items) {
itemCount = numberof(items);
do {
hasChanged = 0;
itemCount--;
for(index = 1; index <= itemCount; index++) {
if(items(index) > items(index+1)) {
items([index,index+1]) = items([index+1,index]);
hasChanged = 1;
}
}
} while(hasChanged);
}</lang>
zkl
<lang zkl>fcn bubbleSort(list){
itemCount := list.len();
do{
hasChanged := False;
foreach index in (itemCount -= 1){
if (list[index] > list[index + 1]){ list.swap(index,index + 1); hasChanged = True; }
} }while(hasChanged); list
}</lang> Or, punting early termination: <lang zkl>fcn bubbleSort(list){
foreach n,index in ([list.len()-1..0,-1],n){
if (list[index] > list[index + 1]) list.swap(index,index + 1);
}
list
}</lang> <lang zkl>bubbleSort("This is a test".split("")).println();</lang>
- Output:
L(" "," "," ","T","a","e","h","i","i","s","s","s","t","t")ZX Spectrum Basic
<lang zxbasic>5000 CLS 5002 LET a$="": FOR f=1 TO 64: LET a$=a$+CHR$ (32+INT (RND*96)): NEXT f 5004 PRINT a$; AT 10,0;"ZigZag BubbleSORT" 5010 LET la=LEN a$ 5011 LET i=1: LET u=0 5020 LET d=0: LET p=(u=0)-(u=1) 5021 LET l=(i AND u=0)+(la-i+u AND u=1) 5030 IF u=0 THEN IF a$(l+1)>=a$(l) THEN GO TO 5050 5031 IF u=1 THEN IF a$(l-1)<=a$(l) THEN GO TO 5050 5040 LET d=1 5042 LET t$=a$(l+p) 5043 LET a$(l+p)=a$(l) 5044 LET a$(l)=t$ 5050 LET l=l+p 5051 PRINT AT 10,21;a$(l);AT 12,0;a$ 5055 IF l<=la-i AND l>=i THEN GO TO 5023 5061 LET i=i+NOT u 5063 LET u=NOT u 5064 IF d AND i<la THEN GO TO 5020 5072 PRINT AT 12,0;a$ 9000 STOP </lang>