//线性表的删除（数组中实现） 
function delete_array_element($array , $i) 
{ 
        $len =  count($array);  
        for ($j= $i; $j<$len; $j ++){ 
                $array[$j] = $array [$j+1]; 
        } 
        array_pop ($array); 
        return $array ; 
} 
//冒泡排序（数组排序） 
function bubble_sort( $array) 
{ 
        $count = count( $array); 
        if ($count <= 0 ) return false; 
        for($i=0 ; $i<$count; $i ++){ 
                for($j=$count-1 ; $j>$i; $j--){ 
                        if ($array[$j] < $array [$j-1]){ 
                                 $tmp = $array[$j]; 
                                 $array[$j] = $array[ $j-1]; 
                                $array [$j-1] = $tmp; 
                        } 
                } 
        } 
        return $array; 
} 
//快速排序（数组排序） 
function quick_sort($array ) { 
        if (count($array) <= 1) return  $array; 
        $key = $array [0]; 
        $left_arr  = array(); 
        $right_arr = array(); 
        for ($i= 1; $i                if ($array[ $i] <= $key) 
                        $left_arr [] = $array[$i]; 
                else 
                         $right_arr[] = $array[$i ]; 
        } 
        $left_arr = quick_sort($left_arr ); 
        $right_arr = quick_sort( $right_arr); 
        return array_merge($left_arr , array($key), $right_arr); 
} 

//------------------------ 
// PHP内置字符串函数实现 
//------------------------ 
//字符串长度 
function strlen ($str) 
{ 
        if ($str == ' ) return 0; 
        $count =  0