Examples of two quick sorting algorithms in PHP, php sorting algorithm_PHP tutorial

PHP two quick sorting algorithm examples, php sorting algorithm

Although in web application development like PHP, we don’t emphasize the importance of sorting too much, because PHP itself already comes with powerful sorting functions such as sort(), but in some important occasions, such as some high-level In the case of concurrency, I think the impact of the sorting algorithm cannot be ignored. So here we introduce recursive sorting and iterative sorting.

Recursive method:

/**
* 递归法实现的快速排序
*/
function quicksort($seq)
{
    $k = $seq[0];
    $x = array();
    $y = array();
    for($i=1; $i< $_size; $i++) {
      if($seq[$i] <= $k) {
        $x[] = $seq[$i];
      } else {
        $y[] = $seq[$i];
      }
    }
    $x = quicksort($x);
    $y = quicksort($y);
    return array_merge($x, array($k), $y);
  } else {
    return $seq;
  }
}

Iterative method:

/**
* 迭代法的快速排序
*/
function quicksortx(&$seq)
{
  $stack = array($seq);
  $sort = array();
  while ($stack) {
    $arr = array_pop($stack);
    if(count($arr) <= 1) {
      if(count($arr) == 1) {
        $sort[] = &$arr[0];
      }
      continue;
    }
    $k = $arr[0];
    $x = array();
    $y = array();
    $_size = count($arr);
    for($i =1 ;$i < $_size; $i++) {
      if($arr[$i] <= $k) {
        $x[] = &$arr[$i];
      } else {
        $y[] = &$arr[$i];
      }
    }
    !empty($y) && array_push($stack, $y);
    array_push($stack, array($arr[0]));
    !empty($x) && array_push($stack, $x);
  }
  return $sort;
}

Use:

/**
*产生一个随机数组
*/
for($i=0;$i<5;$i++){
  $testArr[]=mt_rand(0,100);
}
var_dump($testArr);
var_dump(quicksort($testArr));

var_dump(quicksortx($testArr));

http://www.bkjia.com/PHPjc/958719.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/958719.htmlTechArticlePHP two quick sorting algorithm examples, php sorting algorithm Although in web application development like PHP, we are not too Emphasize the importance of sorting, because PHP itself has brought such things as sort(), etc...