Quick Sort Recursive version PHP implementation

This article introduces the content of the quick sort recursive version of PHP implementation, has a certain reference value, now share to everyone, the need for friends can refer to

Today began to review the algorithm, even the most familiar with the fast line is not written out, shame, put the code, for later use it

function QSort (array & $a, $low, $high) {       if ($low >= $high) {        return;    }    $index = partition ($a, $low, $high);    QSort ($a, $low, $index-1);    QSort ($a, $index +1, $high);}

The element is mutually assignable than the Exchange efficiency function partition (array & $a, $low, $high) {    $temp = $a [$low];    while ($low < $high) {while        ($low < $high && $a [$high] >= $temp) {             --$high;        }           $a [$low] = $a [$high];        while ($low < $high && $a [$low] <= $temp) {            + + $low;        }           $a [$high] = $a [$low];    }       $a [$low] = $temp;    return $low;}

$a = [0,20,7,-1,6,2,6,2,8,9,0,1];
QSort ($a, 0, count ($a)-1);

Var_dump (Implode (', ', $a));

Results showing: -1,0,0,1,2,2,6,6,7,8,9,20