常见排序算法（PHP实现）

function InsertSort($arr){

    $num  =  count($arr);



    for($i  =  1;  $i  <  $num;  $i++){

        $key  =  $arr[$i];

        for($j  =  $i  -  1;  $j  >=  0;  $j--){

            if($arr[$j]  >  $key){

                $arr[$j  +  1]  =  $arr[$j];

                $arr[$j]  =  $key;

            }

        }

    }

    return $arr;

}



function BubbleSort($arr){

    $num = count($arr);



    for( $i = 1; $i < $num; $i++ ){

        for($j = $num -1; $j >= $i; $j-- ){

            if( $arr[$j] < $arr[$j - 1] ){

                $tmp_val = $arr[$j - 1];

                $arr[$j - 1] = $arr[$j];

                $arr[$j] = $tmp_val;

            }

        }

    }

    return $arr;

}





function BucketSort($arr){

    $bucket = array();



    $idx = 0;



    foreach ($arr as $value) {

        if(!is_int($value)) continue;



        $bucket[$value] = $value;



        if($value > $idx) $idx = $value;

    }



    $rst = array();

    for($i = 0; $i <= $idx; $i++){

        if(isset($bucket[$i])){

            $rst[] = $bucket[$i];

        }

    }



    return $rst;

}



function ExchangeSort($arr){

    $num = count($arr);



    for($i = 0; $i < $num -1; $i++){

        for($j = $i + 1; $j < $num; $j++){

            if($arr[$i] > $arr[$j]){

                $tmp = $arr[$i];

                $arr[$i] = $arr[$j];

                $arr[$j] = $tmp;

            }

        }

    }

    return $arr;

}



function QuickSort($arr){

    $num = count($arr);



    $l_num = $r_num = 0;

    $left = $right = array();



    for($i = 1; $i < $num; $i++){

        if($arr[$i] >= $arr[0]){

            $right[] = $arr[$i];

            $r_num++;

        }else{

            $left[] = $arr[$i];

            $l_num++;

        }

    }



    if($l_num > 1){

        $left = QuickSort($left);

    }



    $left[] = $arr[0];



    if($r_num > 1){

        $right = QuickSort($right);

    }



    for($i = 0; $i < $r_num; $i++){

        $left[] = $right[$i];

    }



    return $left;

}



function PigeonholeSort($arr){

    $pigeonhole = array();



    foreach ($arr as $value) {

        if(!is_int($value)) continue;



        if(isset($pigeonhole[$value]))

            $pigeonhole[$value]++;

        else

            $pigeonhole[$value] = 0;

    }



    $rst = array();



    $i = 0;

    while($pigeonhole[$i]){

        for($j = 0; $j < $pigeonhole[$i]; $j++){

            $rst[] = $i;

        }

        $i++;

    }



    return $rst;

}