2018-08-02

php实现组合枚举算法

源码

        <?php
        function combination($arr, $len, $str = "", &$result = array()) {
        $arrLen = count($arr);
        if ($len == 0)
                $result[] = $str;
        else {
                for ($i = 0; $i < $arrLen - $len + 1; $i++) {
                        $tmp = array_shift($arr);
                        $value = !empty($str) ? $str . '#' . $tmp : $tmp;
                        combination($arr, $len - 1, $value, $result);
                }
        }
        return $result;
        }
        $arr = [
            1,2,3
        ];
        $result = combination($arr,2);
        print_r($result);