Sorting algorithms/Cocktail sort
From Rosetta Code
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 | Strand sort
Other Sorts
Bead sort | Bogosort | Counting sort | Pancake sort | Permutation sort | Radix sort | Sleep sort | Stooge sort
| This page uses content from Wikipedia. The original article was at Cocktail sort. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) |
The cocktail shaker sort is an improvement on the Bubble Sort. The improvement is basically that values "bubble" both directions through the array, because on each iteration the cocktail shaker sort bubble sorts once forwards and once backwards. Pseudocode for the algorithm (from wikipedia):
function cocktailSort( A : list of sortable items )
do
swapped := false
for each i in 0 to length( A ) - 2 do
if A[ i ] > A[ i+1 ] then // test whether the two
// elements are in the wrong
// order
swap( A[ i ], A[ i+1 ] ) // let the two elements
// change places
swapped := true;
if swapped = false then
// we can exit the outer loop here if no swaps occurred.
break do-while loop;
swapped := false
for each i in length( A ) - 2 down to 0 do
if A[ i ] > A[ i+1 ] then
swap( A[ i ], A[ i+1 ] )
swapped := true;
while swapped; // if no elements have been swapped,
// then the list is sorted
[edit] ActionScript
function cocktailSort(input:Array):Array {
do {
var swapped:Boolean=false;
for (var i:uint = 0; i < input.length-1; i++) {
if (input[i]>input[i+1]) {
var tmp=input[i];
input[i]=input[i+1];
input[i+1]=tmp;
swapped=true;
}
}
if (! swapped) {
break;
}
for (i = input.length -2; i >= 0; i--) {
if (input[i]>input[i+1]) {
tmp=input[i];
input[i]=input[i+1];
input[i+1]=tmp;
swapped=true;
}
}
} while (swapped);
return input;
}
[edit] Ada
with Ada.Text_Io; use Ada.Text_Io;
procedure Cocktail_Sort_Test is
procedure Cocktail_Sort (Item : in out String) is
procedure Swap(Left, Right : in out Character) is
Temp : Character := Left;
begin
Left := Right;
Right := Temp;
end Swap;
Swapped : Boolean := False;
begin
loop
for I in 1..Item'Last - 1 loop
if Item(I) > Item(I + 1) then
Swap(Item(I), Item(I + 1));
Swapped := True;
end if;
end loop;
if not Swapped then
for I in reverse 1..Item'Last - 1 loop
if Item(I) > Item(I + 1) then
Swap(Item(I), Item(I + 1));
Swapped := True;
end if;
end loop;
end if;
exit when not Swapped;
Swapped := False;
end loop;
end Cocktail_Sort;
Data : String := "big fjords vex quick waltz nymph";
begin
Put_Line(Data);
Cocktail_Sort(Data);
Put_Line(Data);
end Cocktail_Sort_Test;
[edit] ALGOL 68
MODE DATA = CHAR;
PROC swap = (REF DATA a,b)VOID:(
DATA tmp:=a; a:=b; b:=tmp
);
PROC cocktail sort = (REF[]DATA a)VOID: (
WHILE
BOOL swapped := FALSE;
FOR i FROM LWB a TO UPB a - 1 DO
IF a[ i ] > a[ i + 1 ] THEN # test whether the two elements are in the wrong order #
swap( a[ i ], a[ i + 1 ] ); # let the two elements change places #
swapped := TRUE
FI
OD;
IF NOT swapped THEN
# we can exit the outer loop here if no swaps occurred. #
break do while loop
FI;
swapped := FALSE;
FOR i FROM UPB a - 1 TO LWB a DO
IF a[ i ] > a[ i + 1 ] THEN
swap( a[ i ], a[ i + 1 ] );
swapped := TRUE
FI
OD;
# WHILE # swapped # if no elements have been swapped, then the list is sorted #
DO SKIP OD;
break do while loop: SKIP
);
[32]CHAR data := "big fjords vex quick waltz nymph";
cocktail sort(data);
print(data)
- Output:
abcdefghiijklmnopqrstuvwxyz
Alternatively - when the data records are large - the data can be manipulated indirectly, thus removing the need to actually swap large chunks of memory as only addresses are swapped.
MODE DATA = REF CHAR;
PROC swap = (REF DATA a,b)VOID:(
DATA tmp:=a; a:=b; b:=tmp
);
PROC (REF[]DATA a)VOID cocktail sort;
[32]CHAR data := "big fjords vex quick waltz nymph";
[UPB data]DATA ref data; FOR i TO UPB data DO ref data[i] := data[i] OD;
cocktail sort(ref data);
FOR i TO UPB ref data DO print(ref data[i]) OD; print(new line);
print((data))
- Output:
abcdefghiijklmnopqrstuvwxyz big fjords vex quick waltz nymph
The above two routines both scan the entire width of the array, in both directions, even though the first and last elements of each sweep had already reached their final destination during the previous pass. The solution is to zig-zag, but have the sweeps shorten and converge on the centre element. This reduces the number of comparisons required by about 50%.
PROC odd even sort = (REF []DATA a)VOID: (
FOR offset FROM 0 DO
BOOL swapped := FALSE;
FOR i FROM LWB a + offset TO UPB a - 1 - offset DO
IF a[ i ] > a[ i + 1 ] THEN # test whether the two elements are in the wrong order #
swap( a[ i ], a[ i + 1 ] ); # let the two elements change places #
swapped := TRUE
FI
OD;
# we can exit the outer loop here if no swaps occurred. #
IF NOT swapped THEN break do od loop FI;
swapped := FALSE;
FOR i FROM UPB a - 1 - offset - 1 BY - 1 TO LWB a + offset DO
IF a[ i ] > a[ i + 1 ] THEN
swap( a[ i ], a[ i + 1 ] );
swapped := TRUE
FI
OD;
# if no elements have been swapped, then the list is sorted #
IF NOT swapped THEN break do od loop FI;
OD;
break do od loop: SKIP
);
[edit] AutoHotkey
contributed by Laszlo on the ahk forum
MsgBox % CocktailSort("")
MsgBox % CocktailSort("xxx")
MsgBox % CocktailSort("3,2,1")
MsgBox % CocktailSort("dog,000000,xx,cat,pile,abcde,1,cat,zz,xx,z")
CocktailSort(var) { ; SORT COMMA SEPARATED LIST
StringSplit array, var, `, ; make array
i0 := 1, i1 := array0 ; start, end
Loop { ; break when sorted
Changed =
Loop % i1-- -i0 { ; last entry will be in place
j := i0+A_Index, i := j-1
If (array%j% < array%i%) ; swap?
t := array%i%, array%i% := array%j%, array%j% := t
,Changed = 1 ; change has happened
}
IfEqual Changed,, Break
Loop % i1-i0++ { ; first entry will be in place
i := i1-A_Index, j := i+1
If (array%j% < array%i%) ; swap?
t := array%i%, array%i% := array%j%, array%j% := t
,Changed = 1 ; change has happened
}
IfEqual Changed,, Break
}
Loop % array0 ; construct string from sorted array
sorted .= "," . array%A_Index%
Return SubStr(sorted,2) ; drop leading comma
}
[edit] AWK
Sort the standard input and print it to standard output
{
line[NR] = $0
}
END { # sort it with cocktail sort
swapped = 0
do {
for(i=1; i < NR; i++) {
if ( line[i] > line[i+1] ) {
t = line[i]
line[i] = line[i+1]
line[i+1] = t
swapped = 1
}
}
if ( swapped == 0 ) break
swapped = 0
for(i=NR-1; i >= 1; i--) {
if ( line[i] > line[i+1] ) {
t = line[i]
line[i] = line[i+1]
line[i+1] = t
swapped = 1
}
}
} while ( swapped == 1 )
#print it
for(i=1; i <= NR; i++) {
print line[i]
}
}
[edit] BBC BASIC
Sorting an integer array. '%' indicates integer variable in BBC BASIC
DEF PROC_ShakerSort(Size%)
Start%=2
End%=Size%
Direction%=1
LastChange%=1
REPEAT
FOR J% = Start% TO End% STEP Direction%
IF data%(J%-1) > data%(J%) THEN
SWAP data%(J%-1),data%(J%)
LastChange% = J%
ENDIF
NEXT J%
End% = Start%
Start% = LastChange% - Direction%
Direction% = Direction% * -1
UNTIL ( ( End% * Direction% ) < ( Start% * Direction% ) )
ENDPROC
[edit] C
#include <stdio.h>
#define try_swap { if (a[i] < a[i - 1])\
{ t = a[i]; a[i] = a[i - 1]; a[i - 1] = t; t = 0;} }
void cocktailsort(int *a, size_t len)
{
size_t i;
int t = 0;
while (!t) {
for (i = 1, t = 1; i < len; i++) try_swap;
if (t) break;
for (i = len - 1, t = 1; i; i--) try_swap;
}
}
int main()
{
int x[] = { 5, -1, 101, -4, 0, 1, 8, 6, 2, 3 };
size_t i, len = sizeof(x)/sizeof(x[0]);
cocktailsort(x, len);
for (i = 0; i < len; i++)
printf("%d\n", x[i]);
return 0;
}
[edit] C++
#include <iostream>
#include <windows.h>
//--------------------------------------------------------------------------------------------------
const int EL_COUNT = 77, LLEN = 11;
//--------------------------------------------------------------------------------------------------
class cocktailSort
{
public:
void sort( int* arr, int len )
{
bool notSorted = true;
while( notSorted )
{
notSorted = false;
for( int a = 0; a < len - 1; a++ )
{
if( arr[a] > arr[a + 1] )
{
sSwap( arr[a], arr[a + 1] );
notSorted = true;
}
}
if( !notSorted ) break;
notSorted = false;
for( int a = len - 1; a > 0; a-- )
{
if( arr[a - 1] > arr[a] )
{
sSwap( arr[a], arr[a - 1] );
notSorted = true;
}
}
}
}
private:
void sSwap( int& a, int& b )
{
int t = a;
a = b; b = t;
}
};
//--------------------------------------------------------------------------------------------------
int main( int argc, char* argv[] )
{
srand( GetTickCount() );
cocktailSort cs;
int arr[EL_COUNT];
for( int x = 0; x < EL_COUNT; x++ )
arr[x] = rand() % EL_COUNT + 1;
std::cout << "Original: " << std::endl << "==========" << std::endl;
for( int x = 0; x < EL_COUNT; x += LLEN )
{
for( int s = x; s < x + LLEN; s++ )
std::cout << arr[s] << ", ";
std::cout << std::endl;
}
//DWORD now = GetTickCount();
cs.sort( arr, EL_COUNT );
//now = GetTickCount() - now;
std::cout << std::endl << std::endl << "Sorted: " << std::endl << "========" << std::endl;
for( int x = 0; x < EL_COUNT; x += LLEN )
{
for( int s = x; s < x + LLEN; s++ )
std::cout << arr[s] << ", ";
std::cout << std::endl;
}
std::cout << std::endl << std::endl << std::endl << std::endl;
//std::cout << now << std::endl << std::endl;
system( "pause" );
return 0;
}
//--------------------------------------------------------------------------------------------------
[edit] C#
public static void cocktailSort(int[] A)
{
bool swapped;
do
{
swapped = false;
for (int i = 0; i <= A.Length - 2; i++)
{
if (A[i] > A[i + 1])
{
//test whether the two elements are in the wrong order
int temp = A[i];
A[i] = A[i + 1];
A[i + 1] = temp;
swapped = true;
}
}
if (!swapped)
{
//we can exit the outer loop here if no swaps occurred.
break;
}
swapped = false;
for (int i = A.Length - 2; i >= 0; i--)
{
if (A[i] > A[i + 1])
{
int temp = A[i];
A[i] = A[i + 1];
A[i + 1] = temp;
swapped = true;
}
}
//if no elements have been swapped, then the list is sorted
} while (swapped);
}
[edit] COBOL
This is procedure division only.
C-SORT SECTION.
C-000.
DISPLAY "SORT STARTING".
MOVE 2 TO WC-START
MOVE WC-SIZE TO WC-END.
MOVE 1 TO WC-DIRECTION
WC-LAST-CHANGE.
PERFORM E-SHAKER UNTIL WC-END * WC-DIRECTION <
WC-START * WC-DIRECTION.
DISPLAY "SORT FINISHED".
C-999.
EXIT.
E-SHAKER SECTION.
E-000.
PERFORM F-PASS VARYING WB-IX-1 FROM WC-START BY WC-DIRECTION
UNTIL WB-IX-1 = WC-END + WC-DIRECTION.
MOVE WC-START TO WC-END.
SUBTRACT WC-DIRECTION FROM WC-LAST-CHANGE GIVING WC-START.
MULTIPLY WC-DIRECTION BY -1 GIVING WC-DIRECTION.
E-999.
EXIT.
F-PASS SECTION.
F-000.
IF WB-ENTRY(WB-IX-1 - 1) > WB-ENTRY(WB-IX-1)
SET WC-LAST-CHANGE TO WB-IX-1
MOVE WB-ENTRY(WB-IX-1 - 1) TO WC-TEMP
MOVE WB-ENTRY(WB-IX-1) TO WB-ENTRY(WB-IX-1 - 1)
MOVE WC-TEMP TO WB-ENTRY(WB-IX-1).
F-999.
EXIT.
[edit] Common Lisp
This version works on lists and vectors alike. The vector implementation is coded directly. The list version uses an intermediate vector.
(defun cocktail-sort-vector (vector predicate &aux (len (length vector)))
(labels ((scan (start step &aux swapped)
(loop for i = start then (+ i step) while (< 0 i len) do
(when (funcall predicate (aref vector i)
(aref vector (1- i)))
(rotatef (aref vector i)
(aref vector (1- i)))
(setf swapped t)))
swapped))
(loop while (and (scan 1 1)
(scan (1- len) -1))))
vector)
(defun cocktail-sort (sequence predicate)
(etypecase sequence
(vector (cocktail-sort-vector sequence predicate))
(list (map-into sequence 'identity
(cocktail-sort-vector (coerce sequence 'vector)
predicate)))))
[edit] D
import std.stdio, std.algorithm;
void cocktailSort(Range)(Range data) {
bool swapped = false;
do {
foreach (i; 0 .. data.length - 1)
if (data[i] > data[i + 1]) {
swap(data[i], data[i + 1]);
swapped = true;
}
if (!swapped)
break;
swapped = false;
foreach_reverse (i; 0 .. data.length - 1)
if (data[i] > data[i + 1]) {
swap(data[i], data[i + 1]);
swapped = true;
}
} while(swapped);
}
void main() {
auto array = ["John", "Kate", "Zerg", "Alice", "Joe", "Jane"];
cocktailSort(array);
writeln(array);
}
- Output:
[Alice, Jane, Joe, John, Kate, Zerg]
[edit] Delphi
Dynamic array is a 0-based array of variable length
Static array is an arbitrary-based array of fixed length
program TestShakerSort;
{$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 ShakerSort(var A: TArray);
var
Item: TItem;
K, L, R, J: Integer;
begin
L:= Low(A) + 1;
R:= High(A);
K:= High(A);
repeat
for J:= R 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;
for J:= L to R 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;
R:= K - 1;
until L > R;
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;
ShakerSort(A);
for I:= Low(A) to High(A) do
Write(A[I]:3);
Writeln;
Readln;
end.
- 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
[edit] E
/** Cocktail sort (in-place) */
def cocktailSort(array) {
def swapIndexes := 0..(array.size() - 2)
def directions := [swapIndexes, swapIndexes.descending()]
while (true) {
for direction in directions {
var swapped := false
for a ? (array[a] > array[def b := a + 1]) in direction {
def t := array[a]
array[a] := array[b]
array[b] := t
swapped := true
}
if (!swapped) { return }
}
}
}
Note that this solution contains no repeated code to handle the forward and reverse passes.
[edit] Euphoria
function cocktail_sort(sequence s)
integer swapped, d
object temp
sequence fromto
fromto = {1,length(s)-1}
swapped = 1
d = 1
while swapped do
swapped = 0
for i = fromto[(1-d)/2+1] to fromto[(1+d)/2+1] by d do
if compare(s[i],s[i+1])>0 then
temp = s[i]
s[i] = s[i+1]
s[i+1] = temp
swapped = 1
end if
end for
d = -d
end while
return s
end function
constant s = rand(repeat(1000,10))
? s
? cocktail_sort(s)
- Output:
{963,398,374,455,53,210,611,285,984,308}
{53,210,285,308,374,398,455,611,963,984}
[edit] Forth
defer precedes ( addr addr -- flag )
\ e.g. ' < is precedes
: sort ( a n --)
1- cells bounds 2>r false
begin
0= dup
while
2r@ ?do
i cell+ @ i @ over over precedes ( mark unsorted )
if i cell+ ! i ! dup xor else drop drop then
1 cells +loop
0= dup
while
2r@ swap 1 cells - ?do
i cell+ @ i @ over over precedes ( mark unsorted )
if i cell+ ! i ! dup xor else drop drop then
-1 cells +loop
repeat then drop 2r> 2drop
;
This is an optimized version:
: sort
1- cells bounds 1
begin
>r over over r@ -rot true -rot
r> 0< if 1 cells - then
?do
i cell+ @ i @ over over precedes ( mark unsorted )
if i cell+ ! i ! dup xor else drop drop then
over cells +loop
>r negate >r swap r@ cells + r> r>
until drop drop drop
;
[edit] Fortran
PROGRAM COCKTAIL
IMPLICIT NONE
INTEGER :: intArray(10) = (/ 4, 9, 3, -2, 0, 7, -5, 1, 6, 8 /)
WRITE(*,"(A,10I5)") "Unsorted array:", intArray
CALL Cocktail_sort(intArray)
WRITE(*,"(A,10I5)") "Sorted array :", intArray
CONTAINS
SUBROUTINE Cocktail_sort(a)
INTEGER, INTENT(IN OUT) :: a(:)
INTEGER :: i, bottom, top, temp
LOGICAL :: swapped
bottom = 1
top = SIZE(a) - 1
DO WHILE (bottom < top )
swapped = .FALSE.
DO i = bottom, top
IF (array(i) > array(i+1)) THEN
temp = array(i)
array(i) = array(i+1)
array(i+1) = temp
swapped = .TRUE.
END IF
END DO
IF (.NOT. swapped) EXIT
DO i = top, bottom + 1, -1
IF (array(i) < array(i-1)) THEN
temp = array(i)
array(i) = array(i-1)
array(i-1) = temp
swapped = .TRUE.
END IF
END DO
IF (.NOT. swapped) EXIT
bottom = bottom + 1
top = top - 1
END DO
END SUBROUTINE Cocktail_sort
END PROGRAM COCKTAIL
[edit] Go
package main
import "fmt"
func main() {
a := []int{170, 45, 75, -90, -802, 24, 2, 66}
fmt.Println("before:", a)
cocktailSort(a)
fmt.Println("after: ", a)
}
func cocktailSort(a []int) {
last := len(a) - 1
for {
swapped := false
for i := 0; i < last; i++ {
if a[i] > a[i+1] {
a[i], a[i+1] = a[i+1], a[i]
swapped = true
}
}
if !swapped {
return
}
swapped = false
for i := last - 1; i >= 0; i-- {
if a[i] > a[i+1] {
a[i], a[i+1] = a[i+1], a[i]
swapped = true
}
}
if !swapped {
return
}
}
}
More generic version that sorts anything that implements sort.Interface:
package main
import (
"sort"
"fmt"
)
func main() {
a := []int{170, 45, 75, -90, -802, 24, 2, 66}
fmt.Println("before:", a)
cocktailSort(sort.IntSlice(a))
fmt.Println("after: ", a)
}
func cocktailSort(a sort.Interface) {
last := a.Len() - 1
for {
swapped := false
for i := 0; i < last; i++ {
if a.Less(i+1, i) {
a.Swap(i, i+1)
swapped = true
}
}
if !swapped {
return
}
swapped = false
for i := last - 1; i >= 0; i-- {
if a.Less(i+1, i) {
a.Swap(i, i+1)
swapped = true
}
}
if !swapped {
return
}
}
}
[edit] Groovy
Solution:
def makeSwap = { a, i, j = i+1 -> print "."; a[[j,i]] = a[[i,j]] }
def checkSwap = { a, i, j = i+1 -> [(a[i] > a[j])].find{ it }.each { makeSwap(a, i, j) } }
def cocktailSort = { list ->
if (list == null || list.size() < 2) return list
def n = list.size()
def swap = checkSwap.curry(list)
while (true) {
def swapped = (0..(n-2)).any(swap) && ((-2)..(-n)).any(swap)
if ( ! swapped ) break
}
list
}
Test:
println cocktailSort([23,76,99,58,97,57,35,89,51,38,95,92,24,46,31,24,14,12,57,78,4])
println cocktailSort([88,18,31,44,4,0,8,81,14,78,20,76,84,33,73,75,82,5,62,70,12,7,1])
println cocktailSort([ 3, 14, 1, 5, 9, 2, 6, 3 ])
println cocktailSort([ 3, 14 ])
println cocktailSort([ 33, 14 ])
- 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] ..............[1, 2, 3, 3, 5, 6, 9, 14] [3, 14] .[14, 33]
[edit] Haskell
cocktailSort :: Ord a => [a] -> [a]
cocktailSort l
| not swapped1 = l
| not swapped2 = reverse $ l1
| otherwise = cocktailSort l2
where (swapped1, l1) = swappingPass (>) (False, []) l
(swapped2, l2) = swappingPass (<) (False, []) l1
swappingPass :: Ord a => (a -> a -> Bool) -> (Bool, [a]) -> [a] -> (Bool, [a])
swappingPass op (swapped, l) (x1 : x2 : xs)
| op x1 x2 = swappingPass op (True, x2 : l) (x1 : xs)
| otherwise = swappingPass op (swapped, x1 : l) (x2 : xs)
swappingPass _ (swapped, l) [x] = (swapped, x : l)
swappingPass _ pair [] = pair
[edit] Io
List do (
cocktailSortInPlace := method(
start := 0
end := size - 2
loop(
swapped := false
for(idx, start, end,
if(at(idx) > at(idx + 1),
swapped := true
swapIndices(idx, idx + 1)
)
)
if(swapped not, break, end := end - 1)
for (idx, end, start, -1,
if(at(idx) > at(idx + 1),
swapped := true
swapIndices(idx, idx + 1)
)
)
if(swapped not, break, start := start + 1)
)
self)
)
l := list(2, 3, 4, 5, 1)
l cocktailSortInPlace println # ==> list(1, 2, 3, 4, 5)
[edit] Icon and Unicon
procedure main() #: demonstrate various ways to sort a list and string
demosort(cocktailsort,[3, 14, 1, 5, 9, 2, 6, 3],"qwerty")
end
procedure cocktailsort(X,op) #: return sorted list
local i,swapped
op := sortop(op,X) # select how and what we sort
swapped := 1
repeat # translation of pseudo code. Contractions used to eliminate second loop.
every (if /swapped then break break else swapped := &null & next) | ( i := 1 to *X-1) |
(if /swapped then break break else swapped := &null & next) | ( i := *X-1 to 1 by -1) do
if op(X[i+1],X[i]) then
X[i+1] :=: X[swapped := i]
return X
end
Note: This example relies on the supporting procedures 'sortop', and 'demosort' in Bubble Sort. The full demosort exercises the named sort of a list with op = "numeric", "string", ">>" (lexically gt, descending),">" (numerically gt, descending), a custom comparator, and also a string.
- Abbreviated example output:
Sorting Demo using procedure cocktailsort
on list : [ 3 14 1 5 9 2 6 3 ]
with op = &null: [ 1 2 3 3 5 6 9 14 ] (0 ms)
...
on string : "qwerty"
with op = &null: "eqrtwy" (0 ms)
[edit] J
bigToLeft=: (([ (>. , <.) {.@]) , }.@])/
smallToLeft=: (([ (<. , >.) {.@]) , }.@])/
cocktailSort=: |. @: (|. @: smallToLeft @: |. @: bigToLeft ^:_)
Test run:
?. 10 $ 10
4 6 8 6 5 8 6 6 6 9
cocktailSort ?. 10 $ 10
4 5 6 6 6 6 6 8 8 9
As is usual with J, /:~ is the preferred method of sorting in practice.
[edit] Java
This algorithm sorts in place. Call it with a copy of the array to preserve the unsorted order.
public static void cocktailSort( int[] A ){
boolean swapped;
do {
swapped = false;
for (int i =0; i<= A.length - 2;i++) {
if (A[ i ] > A[ i + 1 ]) {
//test whether the two elements are in the wrong order
int temp = A[i];
A[i] = A[i+1];
A[i+1]=temp;
swapped = true;
}
}
if (!swapped) {
//we can exit the outer loop here if no swaps occurred.
break;
}
swapped = false;
for (int i= A.length - 2;i>=0;i--) {
if (A[ i ] > A[ i + 1 ]) {
int temp = A[i];
A[i] = A[i+1];
A[i+1]=temp;
swapped = true;
}
}
//if no elements have been swapped, then the list is sorted
} while (swapped);
}
[edit] Lua
function cocktailSort( A )
local swapped
repeat
swapped = false
for i = 1, #A - 1 do
if A[ i ] > A[ i+1 ] then
A[ i ], A[ i+1 ] = A[ i+1 ] ,A[i]
swapped=true
end
end
if swapped == false then
break -- repeatd loop;
end
for i = #A - 1,1,-1 do
if A[ i ] > A[ i+1 ] then
A[ i ], A[ i+1 ] = A[ i+1 ] , A[ i ]
swapped=true
end
end
until swapped==false
end
- Example:
list = { 5, 6, 1, 2, 9, 14, 2, 15, 6, 7, 8, 97 }
cocktailSort(list)
for i=1,#list do
print(list[i]j)
end
[edit] Mathematica
cocktailSort[A_List] := Module[ { swapped = True },
While[ swapped == True,
swapped=False;
For[ i = 1, i< Length[A]-1,i++,
If[ A[[i]] > A[[i+1]], A[[i;;i+1]] = A[[i+1;;i;;-1]]; swapped=True;]
];
If[swapped == False, Break[]];
swapped=False;
For [ i= Length[A]-1, i > 0, i--,
If[ A[[i]] > A[[i+1]], A[[i;;i+1]] = A[[i+1;;i;;-1]]; swapped = True;]
]]]
- Example:
cocktailSort[{2,1,5,3,6}]
->{1,2,3,5,6}
[edit] MATLAB / Octave
function list = cocktailSort(list)
%We have to do this because the do...while loop doesn't exist in MATLAB
swapped = true;
while swapped
%Bubble sort down the list
swapped = false;
for i = (1:numel(list)-1)
if( list(i) > list(i+1) )
list([i i+1]) = list([i+1 i]); %swap
swapped = true;
end
end
if ~swapped
break
end
%Bubble sort up the list
swapped = false;
for i = (numel(list)-1:-1:1)
if( list(i) > list(i+1) )
list([i i+1]) = list([i+1 i]); %swap
swapped = true;
end %if
end %for
end %while
end %cocktail sort
- Sample usage:
cocktailSort([6 3 7 8 5 1 2 4 9])
ans =
1 2 3 4 5 6 7 8 9
[edit] MAXScript
fn cocktailSort arr =
(
local swapped = true
while swapped do
(
swapped = false
for i in 1 to (arr.count-1) do
(
if arr[i] > arr[i+1] then
(
swap arr[i] arr[i+1]
swapped = true
)
)
if not swapped then exit
for i in (arr.count-1) to 1 by -1 do
(
if arr[i] > arr[i+1] then
(
swap arr[i] arr[i+1]
swapped = true
)
)
)
return arr
)
[edit] 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 = cocktailSort(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 cocktailSort(A = String[]) public constant binary returns String[]
Alength = A.length
swapped = isFalse
loop label swapped until \swapped
swapped = isFalse
loop i_ = 0 to Alength - 2
if A[i_].compareTo(A[i_ + 1]) > 0 then do
swap = A[i_ + 1]
A[i_ + 1] = A[i_]
A[i_] = swap
swapped = isTrue
end
end i_
if \swapped then do
leave swapped
end
swapped = isFalse
loop i_ = Alength - 2 to 0 by -1
if A[i_].compareTo(A[i_ + 1]) > 0 then do
swap = A[i_ + 1]
A[i_ + 1] = A[i_]
A[i_] = swap
swapped = isTrue
end
end i_
end swapped
return A
method isTrue public constant binary returns boolean
return 1 == 1
method isFalse public constant binary returns boolean
return \isTrue
- 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
[edit] Objeck
bundle Default {
class Cocktail {
function : Main(args : String[]) ~ Nil {
values := [5, -1, 101, -4, 0, 1, 8, 6, 2, 3 ];
CocktailSort(values);
each(i : values) {
values[i]->PrintLine();
};
}
function : CocktailSort(a : Int[]) ~ Nil {
swapped : Bool;
do {
swapped := false;
continue := true;
for (i := 0; i <= a->Size() - 2 & continue; i += 1;) {
if(a[i] > a[i + 1]) {
temp := a[i];
a[i] := a[i+1];
a[i+1] := temp;
swapped := true;
};
};
if(swapped <> true) {
continue := false;
};
swapped := false;
for(i := a->Size() - 2; i >= 0; i -= 1;){
if(a[i] > a[i + 1]) {
temp := a[i];
a[i] := a[i+1];
a[i + 1] := temp;
swapped := true;
};
};
}
while(swapped);
}
}
}
[edit] OCaml
let swap a i j =
let tmp = a.(i) in
a.(i) <- a.(j);
a.(j) <- tmp;
;;
let cocktail_sort a =
let begin_ = ref(-1)
and end_ = ref(Array.length a - 2) in
let swapped = ref true in
try while !swapped do
swapped := false;
incr begin_;
for i = !begin_ to !end_ do
if a.(i) > a.(i+1) then begin
swap a (i) (i+1);
swapped := true;
end;
done;
if !swapped = false then raise Exit;
swapped := false;
decr end_;
for i = !end_ downto !begin_ do
if a.(i) > a.(i+1) then begin
swap a (i) (i+1);
swapped := true
end;
done;
done with Exit -> ()
;;
let () =
let a = [| 3; 7; 4; 9; 6; 1; 8; 5; 2; |] in
cocktail_sort a;
Array.iter (Printf.printf " %d") a;
print_newline();
;;
- Output:
1 2 3 4 5 6 7 8 9
[edit] Octave
function sl = cocktailsort(l)
swapped = true;
while(swapped)
swapped = false;
for i = 1:(length(l)-1)
if ( l(i) > l(i+1) )
t = l(i);
l(i) = l(i+1);
l(i+1) = t;
swapped = true;
endif
endfor
if ( !swapped )
break;
endif
swapped = false;
for i = (length(l)-1):-1:1
if ( l(i) > l(i+1) )
t = l(i);
l(i) = l(i+1);
l(i+1) = t;
swapped = true;
endif
endfor
endwhile
sl = l;
endfunction
- Example:
s = cocktailsort([5, -1, 101, -4, 0, \
1, 8, 6, 2, 3 ]);
disp(s);
[edit] ooRexx
/* Rexx */
placesList = .array~of( -
"UK London", "US New York" , "US Boston", "US Washington" -
, "UK Washington", "US Birmingham" , "UK Birmingham", "UK Boston" -
)
sortedList = cocktailSort(placesList~allItems())
lists = .array~of(placesList, sortedList)
loop ln = 1 to lists~items()
cl = lists[ln]
loop ct = 1 to cl~items()
say cl[ct]
end ct
say
end ln
return
exit
::routine cocktailSort
use arg A
Alength = A~items()
swapped = .false
loop label swaps until \swapped
swapped = .false
loop i_ = 1 to Alength - 1
if A[i_] > A[i_ + 1] then do
swap = A[i_ + 1]
A[i_ + 1] = A[i_]
A[i_] = swap
swapped = .true
end
end i_
if \swapped then do
leave swaps
end
swapped = .false
loop i_ = Alength - 1 to 1 by -1
if A[i_] > A[i_ + 1] then do
swap = A[i_ + 1]
A[i_ + 1] = A[i_]
A[i_] = swap
swapped = .true
end
end i_
end swaps
return A
- 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
[edit] Oz
declare
proc {CocktailSort Arr}
proc {Swap I J}
Arr.J := (Arr.I := Arr.J) %% assignment returns the old value
end
IsSorted = {NewCell false}
Up = {List.number {Array.low Arr} {Array.high Arr}-1 1}
Down = {Reverse Up}
in
for until:@IsSorted break:Break do
for Range in [Up Down] do
IsSorted := true
for I in Range do
if Arr.I > Arr.(I+1) then
IsSorted := false
{Swap I I+1}
end
end
if @IsSorted then {Break} end
end
end
end
Arr = {Tuple.toArray unit(10 9 8 7 6 5 4 3 2 1)}
in
{CocktailSort Arr}
{Inspect Arr}
[edit] PARI/GP
cocktailSort(v)={
while(1,
my(done=1);
for(i=2,#v,
if(v[i-1]>v[i],
my(t=v[i-1]);
v[i-1]=v[i];
v[i]=t;
done=0
)
);
if(done, return(v));
done=1;
forstep(i=#v,2,-1,
if(v[i-1]>v[i],
my(t=v[i-1]);
v[i-1]=v[i];
v[i]=t;
done=0
)
);
if(done, return(v))
)
};
[edit] Pascal
See Delphi
[edit] Perl
use strict;
use warnings;
my @B=qw(t h e q u i c k b r o w n f o x j u m p s o v e r t h e l a z y d o g);
print "@B\n";
my @C=cocktailSort(@B);
print "@C\n";
################### cocktailSort #####################
sub cocktailSort { #( A : list of sortable items ) defined as:
my @A = @_;
my $swapped = 1;
while ($swapped == 1) {
$swapped = 0;
for (my $i=0; $i<($#A-1); $i+=1) {
if ($A[$i] gt $A[$i+1]) { # test whether the two
# elements are in the wrong
# order
($A[$i+1], $A[$i])=($A[$i], $A[$i+1]); # let the two elements
# change places
$swapped = 1;
}
}
if ($swapped == 0) {
# we can exit the outer loop here if no swaps occurred.
print "no more swaps";
}
else {
$swapped = 0;
for (my $i=($#A-1); $i>0 ; $i-=1) {
if($A[$i] gt $A[$i+1]) {
($A[$i+1], $A[$i])=($A[$i], $A[$i+1]);
$swapped = 1;
}
}
}
# if no elements have been swapped,
# then the list is sorted
}
return (@A);
#end sub
}
[edit] Perl 6
sub cocktail_sort ( @a ) {
my $range = 0 ..^ @a.end;
loop {
my $swapped_forward = 0;
for $range.list -> $i {
if @a[$i] > @a[$i+1] {
@a[ $i, $i+1 ] .= reverse;
$swapped_forward = 1;
}
}
last if not $swapped_forward;
my $swapped_backward = 0;
for $range.reverse -> $i {
if @a[$i] > @a[$i+1] {
@a[ $i, $i+1 ] .= reverse;
$swapped_backward = 1;
}
}
last if not $swapped_backward;
}
return @a;
}
my @weights = (^50).map: { 100 + ( 1000.rand.Int / 10 ) };
say @weights.sort.Str eq @weights.&cocktail_sort.Str ?? 'ok' !! 'not ok';
[edit] PHP
function cocktailSort($arr){
if (is_string($arr)) $arr = str_split(preg_replace('/\s+/','',$arr));
do{
$swapped = false;
for($i=0;$i<count($arr);$i++){
if(isset($arr[$i+1])){
if($arr[$i] > $arr[$i+1]){
list($arr[$i], $arr[$i+1]) = array($arr[$i+1], $arr[$i]);
$swapped = true;
}
}
}
if ($swapped == false) break;
$swapped = false;
for($i=count($arr)-1;$i>=0;$i--){
if(isset($arr[$i-1])){
if($arr[$i] < $arr[$i-1]) {
list($arr[$i],$arr[$i-1]) = array($arr[$i-1],$arr[$i]);
$swapped = true;
}
}
}
}while($swapped);
return $arr;
}
$arr = array(5, 1, 7, 3, 6, 4, 2);
$arr2 = array("John", "Kate", "Alice", "Joe", "Jane");
$strg = "big fjords vex quick waltz nymph";
$arr = cocktailSort($arr);
$arr2 = cocktailSort($arr2);
$strg = cocktailSort($strg);
echo implode(',',$arr) . '<br>';
echo implode(',',$arr2) . '<br>';
echo implode('',$strg) . '<br>';
- Output:
1,2,3,4,5,6,7 Alice,Jane,Joe,John,Kate abcdefghiijklmnopqrstuvwxyz
[edit] PicoLisp
(de cocktailSort (Lst)
(use (Swapped L)
(loop
(off Swapped)
(setq L Lst)
(while (cdr L)
(when (> (car L) (cadr L))
(xchg L (cdr L))
(on Swapped) )
(pop 'L) )
(NIL Swapped Lst)
(off Swapped)
(loop
(setq L (prior L Lst)) # Not recommended (inefficient)
(when (> (car L) (cadr L))
(xchg L (cdr L))
(on Swapped) )
(T (== Lst L)) )
(NIL Swapped Lst) ) ) )
- Output:
: (cocktailSort (make (do 9 (link (rand 1 999))))) -> (1 167 183 282 524 556 638 891 902) : (cocktailSort (make (do 9 (link (rand 1 999))))) -> (82 120 160 168 205 226 408 708 719)
[edit] PL/I
cocktail: procedure (A);
declare A(*) fixed;
declare t fixed;
declare stable bit (1);
declare (i, n) fixed binary (31);
n = hbound(A,1);
do until (stable);
stable = '1'b;
do i = 1 to n-1, n-1 to 1 by -1;
if A(i) > A(i+1) then
do; stable = '0'b; /* still unsorted, so set false. */
t = A(i); A(i) = A(i+1); A(i+1) = t;
end;
end;
end;
end cocktail;
[edit] PowerShell
Based on the entry for PowerShell in Bubble Sort
function CocktailSort ($a) {
$l = $a.Length
$m = 0
if( $l -gt 1 )
{
$hasChanged = $true
:outer while ($hasChanged) {
$hasChanged = $false
$l--
for ($i = $m; $i -lt $l; $i++) {
if ($a[$i] -gt $a[$i+1]) {
$a[$i], $a[$i+1] = $a[$i+1], $a[$i]
$hasChanged = $true
}
}
if(-not $hasChanged) {
break outer
}
$hasChanged = $false
for ($i = $l; $i -gt $m; $i--) {
if ($a[$i-1] -gt $a[$i]) {
$a[$i-1], $a[$i] = $a[$i], $a[$i-1]
$hasChanged = $true
}
}
$m++
}
}
$a
}
$l = 10; CocktailSort ( 1..$l | ForEach-Object { $Rand = New-Object Random }{ $Rand.Next( -( $l - 1 ), $l - 1 ) } )
[edit] Prolog
ctail(_, [], Rev, Rev, sorted) :- write(Rev), nl.
ctail(fwrd, [A,B|T], In, Rev, unsorted) :- A > B, !,
ctail(fwrd, [B,A|T], In, Rev, _).
ctail(bkwd, [A,B|T], In, Rev, unsorted) :- A < B, !,
ctail(bkwd, [B,A|T], In, Rev, _).
ctail(D,[A|T], In, Rev, Ch) :- !, ctail(D, T, [A|In], Rev, Ch).
cocktail([], []).
cocktail(In, [Min|Out]) :-
ctail(fwrd, In, [], [Max|Rev], SFlag),
( SFlag=sorted->reverse([Max|Rev], [Min|Out]);
(ctail(bkwd, Rev, [Max], [Min|Tmp], SortFlag),
(SortFlag=sorted->Out=Tmp; !, cocktail(Tmp, Out)))).
test :- In = [8,9,1,3,4,2,6,5,4],
writef(' input=%w\n', [In]),
cocktail(In, R),
writef('-> %w\n', [R]).
Example:
?- test. input=[8,9,1,3,4,2,6,5,4] [9,4,5,6,2,4,3,1,8] [1,8,2,3,4,4,6,5,9] [9,8,5,6,4,4,3,2] [2,3,4,4,5,6,8,9] [9,8,6,5,4,4,3] -> [1,2,3,4,4,5,6,8,9]
[edit] PureBasic
The following approach improves on the method in the pseudo-code by not examining indexes on either end of the array that have already been sorted by reducing the index range on each subsequent pass.
;sorts an array of integers
Procedure cocktailSort(Array a(1))
Protected index, hasChanged, low, high
low = 0
high = ArraySize(a()) - 1
Repeat
hasChanged = #False
For index = low To high
If a(index) > a(index + 1)
Swap a(index), a(index + 1)
hasChanged = #True
EndIf
Next
high - 1
If hasChanged = #False
Break ;we can exit the outer loop here if no changes were made
EndIf
hasChanged = #False
For index = high To low Step -1
If a(index) > a(index + 1)
Swap a(index), a(index + 1)
hasChanged = #True
EndIf
Next
low + 1
Until hasChanged = #False ;if no elements have been changed, then the array is sorted
EndProcedure
[edit] Python
This implementation takes advantage of the identical processing of the two for loops and that a range is a first-class object in Python.
def cocktailSort(A):
up = range(len(A)-1)
while True:
for indices in (up, reversed(up)):
swapped = False
for i in indices:
if A[i] > A[i+1]:
A[i], A[i+1] = A[i+1], A[i]
swapped = True
if not swapped:
return
- Usage:
test1 = [7, 6, 5, 9, 8, 4, 3, 1, 2, 0]
cocktailSort(test1)
print test1
#>>> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
test2=list('big fjords vex quick waltz nymph')
cocktailSort(test2)
print ''.join(test2)
#>>> abcdefghiijklmnopqrstuvwxyz
[edit] R
cocktailsort <- function(x)
{
lenx <- length(x)
repeat
{
swapped <- FALSE
for(i in 1:(lenx-1))
{
if(x[i] > x[i+1])
{
temp <- x[i]
x[i] <- x[i+1]
x[i+1] <- temp
swapped <- TRUE
}
}
if(!swapped) break
swapped <- FALSE
for(i in (lenx-1):1)
{
if(x[i] > x[i+1])
{
temp <- x[i]
x[i] <- x[i+1]
x[i+1] <- temp
swapped <- TRUE
}
}
if(!swapped) break
}
x
}
print(cocktailsort(c(5, -1, 101, -4, 0, 1, 8, 6, 2, 3)))
[edit] REXX
[edit] version handles blanks
This REXX version can handle an array that may contain blanks or spaces.
/*REXX program sorts an array using the cocktail-sort method, a.k.a.: */
/* bidirectional bubble sort, */
/* cocktail shaker sort, */
/* a selection sort variation,*/
/* ripple sort, */
/* shuffle sort, */
/* shuttle sort, */
/* happy hour sort, */
/* a bubble sort variation. */
call gen@ /*generate some array elements. */
call show@ 'before sort' /*show unsorted array elements.*/
call cocktailSort highItem /*invoke cocktail sort subroutine*/
call show@ ' after sort' /*show sorted array elements.*/
exit /*stick a fork in it, we're done.*/
/*──────────────────────────────────COCKTAILSORT subroutine─────────────*/
cocktailSort: procedure expose @.; parse arg N /*N=# of items.*/
do until done; done=1
do j=1 for N-1; jp=j+1
if @.j>@.jp then do; done=0; _=@.j; @.j=@.jp; @.jp=_; end
end /*j*/
if done then leave /*No swaps done? Then we're done*/
do k=N-1 for N-1 by -1; kp=k+1
if @.k>@.kp then do; done=0; _=@.k; @.k=@.kp; @.kp=_; end
end /*k*/
end /*until*/
return
/*──────────────────────────────────GEN@ subroutine─────────────────────*/
gen@: @.='' /*assign default value for stem. */
@.1 ='---the 22 card tarot deck (larger deck has 56 additional cards in 4 suits)---'
@.2 ='==========symbol====================pip======================================'
@.3 ='the juggler ◄─── I'
@.4 ='the high priestess [Popess] ◄─── II'
@.5 ='the empress ◄─── III'
@.6 ='the emperor ◄─── IV'
@.7 ='the hierophant [Pope] ◄─── V'
@.8 ='the lovers ◄─── VI'
@.9 ='the chariot ◄─── VII'
@.10='justice ◄─── VIII'
@.11='the hermit ◄─── IX'
@.12='fortune [the wheel of] ◄─── X'
@.13='strength ◄─── XI'
@.14='the hanging man ◄─── XII'
@.15='death [often unlabeled] ◄─── XIII'
@.16='temperance ◄─── XIV'
@.17='the devil ◄─── XV'
@.18='lightning [the tower] ◄─── XVI'
@.18='the stars ◄─── XVII'
@.20='the moon ◄─── XVIII'
@.21='the sun ◄─── XIX'
@.22='judgment ◄─── XX'
@.23='the world ◄─── XXI'
@.24='the fool [often unnumbered] ◄─── XXII'
do i=1 while @.i\==''; end /*find how many entries in array.*/
highItem=i-1 /*adjust for DO loop advancement.*/
return
/*──────────────────────────────────SHOW@ subroutine────────────────────*/
show@: widthH=length(highItem) /*the maximum width of any line. */
do j=1 for highItem
say 'element' right(j,widthH) arg(1)":" @.j
end
say copies('─',79) /*show a separator line or fence.*/
return
- Output:
element 1 before sort: ---the 22 card tarot deck (larger deck has 56 additional cards in 4 suits)--- element 2 before sort: ==========symbol=====================pip===================================== element 3 before sort: the juggler ◄─── I element 4 before sort: the high priestess [Popess] ◄─── II element 5 before sort: the empress ◄─── III element 6 before sort: the emperor ◄─── IV element 7 before sort: the hierophant [Pope] ◄─── V element 8 before sort: the lovers ◄─── VI element 9 before sort: the chariot ◄─── VII element 10 before sort: justice ◄─── VIII element 11 before sort: the hermit ◄─── IX element 12 before sort: fortune [the wheel of] ◄─── X element 13 before sort: strength ◄─── XI element 14 before sort: the hanging man ◄─── XII element 15 before sort: death [often unlabeled] ◄─── XIII element 16 before sort: temperance ◄─── XIV element 17 before sort: the devil ◄─── XV element 18 before sort: the stars ◄─── XVII ──────────────────────────────────────────────────────────────────────────────── element 1 after sort: ---the 22 card tarot deck (larger deck has 56 additional cards in 4 suits)--- element 2 after sort: ==========symbol=====================pip===================================== element 3 after sort: death [often unlabeled] ◄─── XIII element 4 after sort: fortune [the wheel of] ◄─── X element 5 after sort: justice ◄─── VIII element 6 after sort: strength ◄─── XI element 7 after sort: temperance ◄─── XIV element 8 after sort: the chariot ◄─── VII element 9 after sort: the devil ◄─── XV element 10 after sort: the emperor ◄─── IV element 11 after sort: the empress ◄─── III element 12 after sort: the hanging man ◄─── XII element 13 after sort: the hermit ◄─── IX element 14 after sort: the hierophant [Pope] ◄─── V element 15 after sort: the high priestess [Popess] ◄─── II element 16 after sort: the juggler ◄─── I element 17 after sort: the lovers ◄─── VI element 18 after sort: the stars ◄─── XVII ────────────────────────────────────────────────────────────────────────────────
[edit] version handles non-blanks
This faster REXX version can handle an array that doen't contain blanks or spaces by using a simplier swap mechanism.
/*──────────────────────────────────COCKTAILSORT2 subroutine────────────*/
cocktailSort2: procedure expose @.; parse arg N /*N=# of items.*/
/*array items may not contain blanks*/
do until done; done=1
do j=1 for N-1; jp=j+1
if @.j>@.jp then parse value 0 @.j @.jp with done @.jp @.j
end /*j*/
if done then leave /*No swaps done? Then we're done*/
do k=N-1 for N-1 by -1; kp=k+1
if @.k>@.kp then parse value 0 @.k @.kp with done @.kp @.k
end /*k*/
end /*until*/
return
[edit] Ruby
class Array
def cocktailsort!
begin
swapped = false
0.upto(length - 2) do |i|
if self[i] > self[i + 1]
self[i], self[i + 1] = self[i + 1], self[i]
swapped = true
end
end
break if not swapped
swapped = false
(length - 2).downto(0) do |i|
if self[i] > self[i + 1]
self[i], self[i + 1] = self[i + 1], self[i]
swapped = true
end
end
end while swapped
self
end
end
ary = [7,6,5,9,8,4,3,1,2,0]
ary.cocktailsort!
# => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[edit] Run BASIC
for i = 1 to 100 ' fill array
a(i) = rnd(0) * 100
next i
' ------- sort -------
beg = 2
siz = 100
whatWay = 1
changed = 1
while changed
changed = 0
FOR i = beg TO siz STEP whatWay
IF a(i-1) > a(i) THEN
hold = a(i)
a(i) = a(i-1)
a(i-1) = hold
changed = i
end if
NEXT i
siz = beg
beg = changed - whatWay
whatWay = 0 - whatWay
wend
' ------ print result --------
for i = 1 to 100
print i;" ";a(i)
next i
end
[edit] Slate
s@(Sequence traits) cocktailSort
[ |swapped|
swapped: False.
s size <= 1 ifTrue: [^ s].
[{0 to: s size - 2. s size - 2 downTo: 0}
do: [|:range| range do: [|:index| (s at: index) > (s at: index + 1) ifTrue: [s swap: index with: index + 1. swapped: True]].
swapped ifFalse: [^ s].
swapped: False].
] loop
].
- Example:
slate[1]> #( 10 9 8 7 6 0 -5) cocktailSort.
{-5. 0. 6. 7. 8. 9. 10}
[edit] Smalltalk
OrderedCollection extend [
swap: indexA and: indexB [
|t|
t := self at: indexA.
self at: indexA put: (self at: indexB).
self at: indexB put: t
]
cocktailSort [
|swapped|
[
swapped := false.
1 to: (self size - 1) do: [ :i |
(self at: i) > (self at: (i+1)) ifTrue: [
self swap: i and: (i+1).
swapped := true
]
].
swapped ifFalse: [ ^ self ].
swapped := false.
(self size - 1) to: 1 by: -1 do: [ :i |
(self at: i) > (self at: (i+1)) ifTrue: [
self swap: i and: (i+1).
swapped := true
]
].
swapped
] whileTrue: [ ].
^ self
]
].
- Example:
(#( 10 9 8 7 6 0 -5) asOrderedCollection cocktailSort) printNl.
[edit] Tcl
package require Tcl 8.5
package require struct::list
proc cocktailsort {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
}
}
if { ! $swapped} {
break
}
set swapped false
for {set i [expr {$len - 2}]} {$i >= 0} {incr i -1} {
set j [expr {$i + 1}]
if {[lindex $A $i] > [lindex $A $j]} {
struct::list swap A $i $j
set swapped true
}
}
}
return $A
}
- Example:
puts [cocktailsort {8 6 4 2 1 3 5 7 9}] ;# => 1 2 3 4 5 6 7 8 9
[edit] Ursala
The same function is used for the traversal in each direction, in one case parameterized by the given predicate and in the other by its negation. Lists are used rather than arrays. The fold combinator (=>) avoids explicit recursion.
#import std
ctsort = ^=+ +^|(==?/~&l+ @r+ ~&x++ @x,^/~&)+ ("p". =><> ~&r?\~&C "p"?lrhPX/~&C ~&rhPlrtPCC)^~/not ~&
test program:
#cast %s
test = ctsort(lleq) 'mdfdguldxisgbxjtqkadfkslakwkyioukdledbig'
- Output:
'aabbddddddeffgggiiijkkkkklllmoqsstuuwxxy'
[edit] VBScript
A few of the streets nearby.
- Implementation
function cocktailSort( a )
dim swapped
dim i
do
swapped = false
for i = 0 to ubound( a ) - 1
if a(i) > a(i+1) then
swap a(i), a(i+1)
swapped = true
end if
next
if not swapped then exit do
swapped = false
for i = ubound( a ) - 1 to 0 step -1
if a(i) > a( i+1) then
swap a(i), a(i+1)
swapped = true
end if
next
if not swapped then exit do
loop
cocktailSort = a
end function
sub swap( byref a, byref b)
dim tmp
tmp = a
a = b
b = tmp
end sub
- Invocation
dim a
a = array( "portcullis", "redoubt", "palissade", "turret", "collins", "the parapet", "the quarterdeck")
wscript.echo join( a, ", ")
dim b
b = cocktailSort( a )
wscript.echo join( b, ", ")
- Output:
portcullis, redoubt, palissade, turret, collins, the parapet, the quarterdeck collins, palissade, portcullis, redoubt, the parapet, the quarterdeck, turret
[edit] XPL0
code ChOut=8, IntOut=11;
proc CocktailSort(A, L); \Sort array A of length L
int A, L;
int Swapped, I, T;
[loop [Swapped:= false;
for I:= 0 to L-2 do
if A(I) > A(I+1) then \test if elements are in wrong order
[T:= A(I); A(I):= A(I+1); A(I+1):= T; \elements change places
Swapped:= true;
];
if Swapped = false then quit; \exit outer loop if no swaps occurred
Swapped:= false;
for I:= L-2 downto 0 do
if A(I) > A(I+1) then
[T:= A(I); A(I):= A(I+1); A(I+1):= T;
Swapped:= true;
];
\if no elements have been swapped then the list is sorted
if not Swapped then quit;
];
];
int A, I;
[A:= [3, 1, 4, 1, -5, 9, 2, 6, 5, 4];
CocktailSort(A, 10);
for I:= 0 to 10-1 do [IntOut(0, A(I)); ChOut(0, ^ )];
]
- Output:
-5 1 1 2 3 4 4 5 6 9
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