<?php function mergeSort(&$arr){	$len = count($arr);		msort($arr,0,$len-1);}function msort(&$arr,$low,$high){	if($low<$high){		$mid = floor(($low+$high)/2);		msort($arr, $low, $mid);		msort($arr,$mid+1,$high);		mergeArray($arr,$low,$mid,$high);	}}function mergeArray(&$arr,$low,$mid,$high){	$i = $low;	$j = $mid+1;		while($i<=$mid && $j<=$high){		if($arr[$i]<$arr[$j]){			$tmp[] = $arr[$i++];		}else{			$tmp[] = $arr[$j++];		}			}		while($i<=$mid){		$tmp[] = $arr[$i++];	}	while($j<=$high){		$tmp[] = $arr[$j++];	}	$len = count($tmp);	for($k=0;$k<$len;$k++){		$arr[$low+$k] = $tmp[$k];	}}$arr = array(1,2,3,7,9,0,4,6,5,1);mergeSort($arr);print_r($arr);?>