在線運行PHP http://www.compileonline.com/execute_php_online.php
1 <?php
2 function swap( &$a, &$b )
3 {
4 $c = $a;
5 $a = $b;
6 $b = $c;
7 }
8
9 /**
10 * quick sort
11 * ascend
12 * in-place
13 */
14 function quick_sort( &$a )
15 {
16 $s = count( $a ); // size of a
17 if ( $s < 2 ) return;
18 $i = 0; // index of pivot, for tracking pivot
19 $pivot = $a[$i];
20 $l = 0; // swap listener, if listens no swap, sort fini
21
22 // swap those smaller than pivot to the left
23 for ( $m = 0; $m < $s; $m++ )
24 {
25 if ( $a[$m] < $a[$i] )
26 {
27 swap( $a[$m], $a[$i] );
28 $i = $m;
29 $l++;
30 }
31 }
32
33 // swap those larger than pivot to the right
34 for ( $n = 0; $n < $i; $n++)
35 {
36 if ( $a[$n] > $a[$i] )
37 {
38 swap( $a[$n], $a[$i] );
39 $i = $n;
40 $l++;
41 }
42 }
43
44 if ( $l == 0 ) return;
45 else $l = 0;
46 quick_sort( $a );
47 }
48
49 $arr = range( 9, 0 );
50 quick_sort( $arr );
51 echo implode( ', ', $arr );
52 ?>
