Sorting algorithms/Bubble sort
From Rosetta Code
< Sorting algorithms(Redirected from Bubble Sort)
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.
Heapsort | Mergesort | Quicksort
O(n log2n) Sorts
Shell Sort
O(n2) Sorts
Bubble Sort | Cocktail Sort | Comb Sort | Gnome Sort | Insertion Sort | Selection Sort
Other Sorts
Bead Sort | Bogosort | Counting Sort | Pancake Sort | Permutation Sort | Stooge 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.
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
[edit] 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;
}
[edit] Ada
Works with: GCC version 4.1.2
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;
[edit] ALGOL 68
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))
)
Output:
Before: +1 +6 +3 +5 +2 +9 +8 +4 +7 +0 After: +0 +1 +2 +3 +4 +5 +6 +7 +8 +9
[edit] 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
}
[edit] AWK
Sort the standard input and print it to standard output.
{ # 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]
}
}
[edit] BASIC
Works with: QuickBasic version 4.5
Translation of: Java Assume numbers are in a DIM of size "size" called "nums".
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
LOOP WHILE(NOT changed)
[edit] BBC BASIC
The Bubble sort is very inefficient for 99% of cases. This subroutine uses a couple of 'tricks' to try and mitigate the inefficiency to a limited extent.
DEF PROC_BubbleSort(Size%)
I%=Size%+1
REPEAT
I%-=1
LastChange%=2
FOR J% = 2 TO I%
IF data%(J%-1) > data%(J%) THEN
SWAP data%(J%-1),data%(J%)
LastChange%=J%
ENDIF
NEXT J%
I%=LastChange%
UNTIL I% = 2
ENDPROC
[edit] C
void swap(int *p)
{
int t = p[0];
p[0] = p[1];
p[1] = t;
}
void sort(int *a, int size)
{
int i,sorted;
do {
sorted = 1;
--size;
for (i=0; i<size; i++)
if (a[i+1] < a[i])
{
swap(a+i);
sorted = 0;
}
} while (!sorted);
}
[edit] C++
Works with: g++ version 4.0.2
#include <iostream>
#include <algorithm>
template< typename ARRAY_TYPE, typename INDEX_TYPE >
void
bubble_sort( ARRAY_TYPE array[], INDEX_TYPE size )
{
bool done = false ;
while( !done )
{
done = true ;
for( INDEX_TYPE i = 0 ; i < size-1 ; i++ )
{
if( array[i] > array[i+1] )
{
done = false ;
ARRAY_TYPE temp = array[i+1] ;
array[i+1] = array[i] ;
array[i] = temp ;
}
}
}
}
template< typename TYPE >
void
print( TYPE val )
{
std::cout << val << " " ;
}
int
main( int argc, char* argv[] )
{
int array[] = { 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 } ;
bubble_sort( array, 10 ) ;
std::for_each( &array[0], &array[10], print<int> ) ;
std::cout << std::endl ;
//But in real life...
int data[] = { 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 } ;
std::sort( data, data+10 ) ;
std::for_each( data, data+10, print<int> ) ;
std::cout << std::endl ;
}
[edit] C#
Works with: C# version 3.0+
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 + " ");
}
}
}
[edit] Clean
Bubble sorting an array in-situ (using destructive updates), using Clean's uniqueness typing. We specified the type of sweep using strictness annotations to improve performance.
import StdEnv
bsort :: *(a e) -> *(a e) | Array a e & < e
bsort array
# (done, array) = sweep 1 True array
= if done array (bsort array)
where
sweep :: !Int !Bool !*(a e) -> (!Bool, !*(a e)) | Array a e & < e
sweep i done array
| i >= size array = (done, array)
# (e1, array) = array![i - 1]
(e2, array) = array![i]
| e1 > e2 = sweep (i + 1) False {array & [i - 1] = e2, [i] = e1}
= sweep (i + 1) done array
Using it to sort an array of a hundred numbers:
Start :: {Int}
Start = bsort {x \\ x <- [100,99..1]}
[edit] 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.
(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])))
Purely functional version working on Clojure sequences:
(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]))
[edit] COBOL
This is a complete program that reads in a file of integers and sorts them.
IDENTIFICATION DIVISION.
PROGRAM-ID. BUBBLESORT.
AUTHOR. DAVE STRATFORD.
DATE-WRITTEN. MARCH 2010.
INSTALLATION. HEXAGON SYSTEMS LIMITED.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
SOURCE-COMPUTER. ICL VME.
OBJECT-COMPUTER. ICL VME.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT FA-INPUT-FILE ASSIGN FL01.
SELECT FB-OUTPUT-FILE ASSIGN FL02.
DATA DIVISION.
FILE SECTION.
FD FA-INPUT-FILE.
01 FA-INPUT-REC.
03 FA-DATA PIC S9(6).
FD FB-OUTPUT-FILE.
01 FB-OUTPUT-REC PIC S9(6).
WORKING-STORAGE SECTION.
01 WA-IDENTITY.
03 WA-PROGNAME PIC X(10) VALUE "BUBBLESORT".
03 WA-VERSION PIC X(6) VALUE "000001".
01 WB-TABLE.
03 WB-ENTRY PIC 9(8) COMP SYNC OCCURS 100000
INDEXED BY WB-IX-1.
01 WC-VARS.
03 WC-SIZE PIC S9(8) COMP SYNC.
03 WC-TEMP PIC S9(8) COMP SYNC.
03 WC-END PIC S9(8) COMP SYNC.
03 WC-LAST-CHANGE PIC S9(8) COMP SYNC.
01 WF-CONDITION-FLAGS.
03 WF-EOF-FLAG PIC X.
88 END-OF-FILE VALUE "Y".
03 WF-EMPTY-FILE-FLAG PIC X.
88 EMPTY-FILE VALUE "Y".
PROCEDURE DIVISION.
A-MAIN SECTION.
A-000.
PERFORM B-INITIALISE.
IF NOT EMPTY-FILE
PERFORM C-SORT.
PERFORM D-FINISH.
A-999.
STOP RUN.
B-INITIALISE SECTION.
B-000.
DISPLAY "*** " WA-PROGNAME " VERSION "
WA-VERSION " STARTING ***".
MOVE ALL "N" TO WF-CONDITION-FLAGS.
OPEN INPUT FA-INPUT-FILE.
SET WB-IX-1 TO 0.
READ FA-INPUT-FILE AT END MOVE "Y" TO WF-EOF-FLAG
WF-EMPTY-FILE-FLAG.
PERFORM BA-READ-INPUT UNTIL END-OF-FILE.
CLOSE FA-INPUT-FILE.
SET WC-SIZE TO WB-IX-1.
B-999.
EXIT.
BA-READ-INPUT SECTION.
BA-000.
SET WB-IX-1 UP BY 1.
MOVE FA-DATA TO WB-ENTRY(WB-IX-1).
READ FA-INPUT-FILE AT END MOVE "Y" TO WF-EOF-FLAG.
BA-999.
EXIT.
C-SORT SECTION.
C-000.
DISPLAY "SORT STARTING".
MOVE WC-SIZE TO WC-END.
PERFORM E-BUBBLE UNTIL WC-END = 1.
DISPLAY "SORT FINISHED".
C-999.
EXIT.
D-FINISH SECTION.
D-000.
OPEN OUTPUT FB-OUTPUT-FILE.
SET WB-IX-1 TO 1.
PERFORM DA-WRITE-OUTPUT UNTIL WB-IX-1 > WC-SIZE.
CLOSE FB-OUTPUT-FILE.
DISPLAY "*** " WA-PROGNAME " FINISHED ***".
D-999.
EXIT.
DA-WRITE-OUTPUT SECTION.
DA-000.
WRITE FB-OUTPUT-REC FROM WB-ENTRY(WB-IX-1).
SET WB-IX-1 UP BY 1.
DA-999.
EXIT.
E-BUBBLE SECTION.
E-000.
MOVE 1 TO WC-LAST-CHANGE.
PERFORM F-PASS VARYING WB-IX-1 FROM 1 BY 1
UNTIL WB-IX-1 = WC-END.
MOVE WC-LAST-CHANGE TO WC-END.
E-999.
EXIT.
F-PASS SECTION.
F-000.
IF WB-ENTRY(WB-IX-1) > WB-ENTRY(WB-IX-1 + 1)
SET WC-LAST-CHANGE TO WB-IX-1
MOVE WB-ENTRY(WB-IX-1) TO WC-TEMP
MOVE WB-ENTRY(WB-IX-1 + 1) TO WB-ENTRY(WB-IX-1)
MOVE WC-TEMP TO WB-ENTRY(WB-IX-1 + 1).
F-999.
EXIT.
[edit] Common Lisp
Bubble sort an sequence in-place, using the < operator for comparison if no comaprison function is provided
(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)))))
(bubble-sort (list 5 4 3 2 1))
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.
(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))))
[edit] D
Works with: DMD version 1.025
import std.stdio;
void bubbleSort(T)(T[] array) {
int itemCount = array.length;
bool hasChanged;
do {
hasChanged = false;
itemCount--;
for (int index = 0; index < itemCount; index++) {
if (array[index] > array[index + 1]) {
T temp = array[index];
array[index] = array[index + 1];
array[index + 1] = temp;
hasChanged = true;
}
}
} while (hasChanged);
}
void main() {
auto array = [10, 9, 8, 7, 6, 5, 4, 3, 2, 1].dup;
// member function invocation syntax for arrays
array.bubbleSort();
foreach (index, value; array)
writefln("array[%d] = %d", index, value);
}
[edit] 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
})
}
(Uses the primitive __loop directly because it happens to map to the termination test for this algorithm well.)
[edit] Eiffel
Works with: EiffelStudio version 6.6 (with provisional loop syntax)
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.
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
The second class is MY_SORTED_SET.
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
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.
[edit] 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! ;
It is possible to pass your own comparison operator to sort!, so you can f.e. sort your sequence backwards with passing [ >=< ] into it.
10 [ 10000 random ] replicate
[ "Before: " write . ]
[ "Natural: " write [ natural-sort! ] keep . ]
[ "Reverse: " write [ [ >=< ] sort! ] keep . ] tri
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 }
[edit] Forth
Sorts the 'cnt' cells stored at 'addr' using the test stored in the deferred word 'bubble-test'. Uses forth local variables for clarity.
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 ;
This is the same algorithm done without the local variables:
: 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 ;
Version with O(n) best case:
: 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 ;
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
[edit] Fortran
SUBROUTINE Bubble_Sort(a)
REAL, INTENT(in out), DIMENSION(:) :: a
REAL :: temp
INTEGER :: i, j
LOGICAL :: swapped = .TRUE.
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
[edit] Groovy
Solution:
def bubbleSort = { list ->
boolean swapped = true
while (swapped) {
swapped = false
(1..<list.size()).each {
boolean doSwap = (list[it - 1] > list[it])
swapped |= doSwap
if (doSwap) { list[(it - 1)..it] = list[it..(it - 1)] }
}
}
list
}
Test Program:
def list = [1,6,3,5,2,9,8,4,7,0]
println list
println bubbleSort(list)
Output:
[1, 6, 3, 5, 2, 9, 8, 4, 7, 0] [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[edit] Haskell
This version checks for changes in a separate step for simplicity, because Haskell has no variables to track them with.
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
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.
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
[edit] HicEst
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
[edit] Icon and Unicon
[edit] Icon
Icon/Unicon implementation of a bubble sort
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,sorted
op := sortop(op,X) # select how and what we sort
while /sorted := "yes" do # the sort
every i := 2 to *X do
if op(X[i],X[i-1]) then {
X[i] :=: X[i-1]
sorted := &null
}
return X
end
Sample 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 ] (0 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. The 'sortop' procedure allows various methods of comparison be selected. 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 can be easily provided as shown by '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.
invocable all # for op
procedure sortop(op,X) #: select how to sort
op := case op of {
"string": "<<"
"numeric": "<"
&null: if type(X[1]) == "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
[edit] Unicon
This Icon solution works in Unicon. A solution that uses Unicon extensions has not been provided.
[edit] J
bubbleSort=: (([ (<. , >.) {.@]) , }.@])/^:_
Test program:
?. 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
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.
[edit] Java
Bubble sorting (ascending) an array of any Comparable type:
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);
}
For descending, simply switch the direction of comparison:
if (comparable[a].compareTo(comparable[b]) < 0){
//same swap code as before
}
[edit] 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;
}
Works with: SEE version 3.0 Works with: OSSP js version 1.6.20070208
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;
}
Example:
var my_arr = ["G", "F", "C", "A", "B", "E", "D"];
my_arr.bubblesort();
print(my_arr);
Output:
A,B,C,D,E,F,G
[edit] 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 )
)
)
[edit] 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};
);
[edit] 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
Example:
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
[edit] 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
[edit] 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')
Output:
17 63 80 55 90 88 25 9 71 38 9 17 25 38 55 63 71 80 88 90
[edit] Mathematica
A rule-based solution is only one line, for large lists this method is not optimal, not so because of the method but because of the usage of patterns in a rule based solution:
BubbleSort[input_] := input //. {a___, i_, j_, b___} /; OrderedQ[{j, i}] :> {a, j, i, b}
Example:
BubbleSort[{10, 3, 7, 1, 4, 3, 8, 13, 9}]
gives back:
{1, 3, 3, 4, 7, 8, 9, 10, 13}
[edit] 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
Sample Output:
bubbleSort([5 3 8 4 9 7 6 2 1])
ans =
1 2 3 4 5 6 7 8 9
[edit] 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
)
-- Usage
myArr = #(9, 8, 7, 6, 5, 4, 3, 2, 1)
myArr = bubbleSort myArr
[edit] 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)
[edit] Modula-3
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;
END;
sorted := FALSE;
END;
END;
END Sort;
END Bubble.
[edit] OCaml
Like the Haskell versions above:
This version checks for changes in a separate step for simplicity.
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
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.
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
[edit] Octave
function s = bubblesort(v)
itemCount = length(v);
do
hasChanged = false;
itemCount--;
for i = 1:itemCount
if ( v(i) > v(i+1) )
t = v(i);
v(i) = v(i+1);
v(i+1) = t;
hasChanged = true;
endif
endfor
until(hasChanged == false)
s = v;
endfunction
v = [9,8,7,3,1,100];
disp(bubblesort(v));
[edit] Oz
In-place sorting of mutable arrays:
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}
Purely-functional sorting of immutable lists:
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]}}
[edit] 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];
}
}
}
Usage:
my @a = (39, 25, 30, 28, 36, 72, 98, 25, 43, 38);
bubble_sort(@a);
[edit] Perl 6
Works with: Rakudo version #24 "Seoul"
sub bubble_sort (@a is rw) {
for ^@a -> $i {
for $i ^..^ @a -> $j {
@a[$j] < @a[$i] and @a[$i, $j] = @a[$j, $i];
}
}
}
[edit] PHP
function bubbleSort( array &$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( $swapped );
}
[edit] PL/I
/* A primitive bubble sort */
bubble_sort: procedure (A);
declare A(*) fixed binary;
declare temp fixed binary;
declare i fixed binary, no_more_swaps bit (1) aligned;
do until (no_more_swaps);
no_more_swaps = true;
do i = lbound(A,1) to hbound(A,1)-1;
if A(i) > A(i+1) then
do; temp = A(i); A(i) = A(i+1); A(i+1) = temp;
no_more_swaps = false;
end;
end;
end;
end bubble_sort;
[edit] PicoLisp
(de bubblesort (Lst)
(let (Len (length Lst) Chg)
(loop
(off Chg)
(map
'((N L)
(when (> (car L) (cadr L))
(xchg L (cdr L))
(on Chg) ) )
(range 1 (dec 'Len))
Lst )
(NIL Chg Lst) ) ) )
[edit] Pop11
define bubble_sort(v);
lvars n=length(v), done=false, i;
while not(done) do
true -> done;
n - 1 -> n;
for i from 1 to n do
if v(i) > v(i+1) then
false -> done;
;;; Swap using multiple assignment
(v(i+1), v(i)) -> (v(i), v(i+1));
endif;
endfor;
endwhile;
enddefine;
;;; Test it
vars ar = { 10 8 6 4 2 1 3 5 7 9};
bubble_sort(ar);
ar =>
[edit] PostScript
/bubblesort{ /x exch def /temp x x length 1 sub get def /i x length 1 sub def /j i 1 sub def
x length 1 sub{ i 1 sub{ x j 1 sub get x j get lt { /temp x j 1 sub get def x j 1 sub x j get put x j temp put }if /j j 1 sub def }repeat /i i 1 sub def /j i 1 sub def }repeat x pstack }def </lang>
[edit] PowerShell
function bubblesort ($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
}
}
}
}
[edit] 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
[edit] 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
[edit] 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))
[edit] Ruby
This example adds the bubblesort! method to the Array object. Below are two different methods that show four different iterating constructs in 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|
a, b = self[i-1], self[i]
a, b = b, a if b < a
end
end
self
end
end
ary = [3, 78, 4, 23, 6, 8, 6]
ary.bubblesort1!
p ary
# => [3, 4, 6, 6, 8, 23, 78]
[edit] 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;
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;
This should be able to sort (in ascending order) any object for which is_lt (less than) is defined.
[edit] Scala
This slightly more complex version of Bubble Sort avoids errors with indices.
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)
}
[edit] 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)))
This solution iteratively finds the fixed point of sort-step. A comparison function must be passed to bubblesort. Example usages:
(bubble-sort (list 1 3 5 9 8 6 4 2) >)
(bubble-sort (string->list "Monkey") char<?)
Here is a recursive bubble sort which sorts list 'l' using the comparator 'f':
(define (bsort f l)
(define (dosort l)
(cond ((equal? (cdr l) '()) l)
((f (car l) (cadr l)) (cons (cadr l) (dosort (cons (car l) (cddr l)))))
(else (cons (car l) (dosort (cdr l))))))
(let ((r (dosort l)))
(cond ((equal? l r) l)
(else (bsort f r)))))
For example, you could do
(bsort > '(3 2 1))
(1 2 3)
[edit] 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;
Original source: [2]
[edit] Smalltalk
A straight translation from the pseudocode above. Swap is done with a block closure.
|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.
[edit] 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<i> = :s(floop)
* # Test and display
bubble(arr,10); str = ''
sloop j = j + 1; str = str arr<j> ' ' :s(sloop)
output = trim(str)
end
Output:
33 99 15 54 1 20 88 47 68 72 1 15 20 33 47 54 68 72 88 99
[edit] SPARK
Works with: SPARK GPL version 2010
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.
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;
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.
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;
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.
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;
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) ] .
[edit] TI-83 BASIC
Input your data into L1 and run this program to organize it.
:L1→L2 :1+dim(L2 :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
[edit] Tcl
uses package struct::list from Library: tcllib
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 $A
}
puts [bubblesort {8 6 4 2 1 3 5 7 9}] ;# => 1 2 3 4 5 6 7 8 9
Idiomatic code uses the builtin lsort instead, which is a stable O(n log n) sort.
[edit] Toka
Toka does not have a bubble sort predefined, but it is easy to code a simple one:
#! A simple Bubble Sort function
value| array count changed |
[ ( address count -- )
to count to array
count 0
[ count 0
[ i array array.get i 1 + array array.get 2dup >
[ i array array.put i 1 + array array.put ]
[ 2drop ] ifTrueFalse
] countedLoop
count 1 - to count
] countedLoop
] is bsort
#! Code to display an array
[ ( array count -- )
0 swap [ dup i swap array.get . ] countedLoop drop cr
] is .array
#! Create a 10-cell array
10 cells is-array foo
#! Fill it with random values
20 1 foo array.put
50 2 foo array.put
650 3 foo array.put
120 4 foo array.put
110 5 foo array.put
101 6 foo array.put
1321 7 foo array.put
1310 8 foo array.put
987 9 foo array.put
10 10 foo array.put
#! Display the array, sort it, and display it again
foo 10 .array
foo 10 bsort
foo 10 .array
[edit] Unicon
See Icon.
[edit] UnixPipes
rm -f _sortpass
reset() {
test -f _tosort || mv _sortpass _tosort
}
bpass() {
(read a; read b
test -n "$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
[edit] Ursala
The bubblesort function is parameterized by a relational predicate.
#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>
output:
<140,212,247,270,315,362,449,532,567,677>
[edit] 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.
[edit] Implementation
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
[edit] Invocation
dim a
a = array( "great eastern", "roe", "stirling", "albany", "leach")
wscript.echo join(a,", ")
bubbleSort a
wscript.echo join(a,", ")
[edit] Output
great eastern, roe, stirling, albany, leach albany, great eastern, leach, roe, stirling
[edit] Visual Basic .NET
Platform: .NET
Works with: Visual Basic .NET version 9.0+
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
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