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    $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） * @param $array * @return array */function quicksort($array){    if (count($array) <= 1) return $array;    $key = $array[0];    $left_arr = array();    $right_arr = array();    for ($i = 1; $i < count($array); $i++) {        if ($array[$i] <= $key)            $left_arr[] = $array[$i];        else            $right_arr[] = $array[$i];    }    $left_arr = quicksort($left_arr);    $right_arr = quicksort($right_arr);    return array_merge($left_arr, array($key), $right_arr);}/** * 字符串长度 * @param $str * @return int */function strlen($str){    if ($str == '') return 0;    $count = 0;    while (1) {        if ($str[$count] != NULL) {            $count++;            continue;        } else {            break;        }    }    return $count;}/** * 截取子串 * @param $str * @param $start * @param null $length * @return string|void */function substr($str, $start, $length = NULL){    $substr = '';    if ($str == '' || $start > strlen($str)) return;    if (($length != NULL) && ($start > 0) && ($length > strlen($str) - $start)) return;    if (($length != NULL) && ($start < 0) && ($length > strlen($str) + $start)) return;    if ($length == NULL) $length = (strlen($str) - $start);    if ($start < 0) {        for ($i = (strlen($str) + $start); $i < (strlen($str) + $start + $length); $i++) {            $substr .= $str[$i];        }    }    if ($length > 0) {        for ($i = $start; $i < ($start + $length); $i++) {            $substr .= $str[$i];        }    }    if ($length < 0) {        for ($i = $start; $i < (strlen($str) + $length); $i++) {            $substr .= $str[$i];        }    }    return $substr;}/** * 字符串翻转 * @param $str * @return int|string */function strrev($str){    $rev_str = '';    if ($str == '') return 0;    for ($i = (strlen($str) - 1); $i >= 0; $i--) {        $rev_str .= $str[$i];    }    return $rev_str;}/** * 字符串比较 * @param $s1 * @param $s2 * @return bool|int */function strcmp($s1, $s2){    if (strlen($s1) < strlen($s2)) return -1;    if (strlen($s1) > strlen($s2)) return 1;    for ($i = 0; $i < strlen($s1); $i++) {        if ($s1[$i] == $s2[$i]) {            continue;        } else {            return false;        }    }    return 0;}/** * 查找字符串 * @param $str * @param $substr * @return bool|int */function strstr($str, $substr){    $m = strlen($str);    $n = strlen($substr);    if ($m < $n) return false;    for ($i = 0; $i <= ($m - $n + 1); $i++) {        $sub = substr($str, $i, $n);        if (strcmp($sub, $substr) == 0) return $i;    }    return false;}/** * 字符串替换 * @param $substr * @param $newsubstr * @param $str * @return bool|string */function str_replace($substr, $newsubstr, $str){    $m = strlen($str);    $n = strlen($substr);    $x = strlen($newsubstr);    if (strchr($str, $substr) == false) return false;    for ($i = 0; $i <= ($m - $n + 1); $i++) {        $i = strchr($str, $substr);        $str = str_delete($str, $i, $n);        $str = str_insert($str, $i, $x);    }    return $str;}/** * 插入一段字符串 * @param $str * @param $i * @param $substr * @return string */function str_insert($str, $i, $substr){    $startstr = '';    $laststr = '';    for ($j = 0; $j < $i; $j++) {        $startstr .= $str[$j];    }    for ($j = $i; $j < strlen($str); $j++) {        $laststr .= $str[$j];    }    $str = ($startstr . $substr . $laststr);    return $str;}/** * 删除一段字符串 * @param $str * @param $i * @param $j * @return string */function str_delete($str, $i, $j){    $startstr = '';    $laststr = '';    for ($c = 0; $c < $i; $c++) {        $startstr .= $str[$c];    }    for ($c = ($i + $j); $c < strlen($str); $c++) {        $laststr .= $str[$c];    }    $str = ($startstr . $laststr);    return $str;}/** * 复制字符串 * @param $s1 * @param $s2 * @return array|void */function strcpy($s1, $s2){    if (strlen($s1) == NULL || !isset($s2)) return;    for ($i = 0; $i < strlen($s1); $i++) {        $s2[] = $s1[$i];    }    return $s2;}/** * 连接字符串 * @param $s1 * @param $s2 */function strcat($s1, $s2){    if (!isset($s1) || !isset($s2)) return;    $newstr = $s1;    for ($i = 0; $i < count($s1); $i++) {        $newstr .= $s1[$i];    }    return $newstr;}

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