php递归如何实现字符串的排列?

Question

输入一个字符串,按字典序打印出该字符串中字符的所有排列。例如输入字符串abc,则打印出由字符a,b,c所能排列出来的所有字符串abc,acb,bac,bca,cab和cba。 结果请按字母顺序输出。

Answer 1

 <?php

    $str = "acdakjflsdaf";

    $data = randStr($str);

    var_dump($data);

    function randStr($str)
    {
        $temp[] = $str;

        $n = strlen($str);
        for ($i = 0; $i < $n; $i++)
        {
            // 把第一个移动到最后一个
            $fir_char = $str{0};

            $str = substr($str, 1);
            $str .= $fir_char;

            $temp[] = $str;
        }

        sort($temp);

        return $temp;
    }

输出结果：

 ---------- Debug PHP ----------
array(13) {
  [0] =>
  string(12) "acdakjflsdaf"
  [1] =>
  string(12) "acdakjflsdaf"
  [2] =>
  string(12) "afacdakjflsd"
  [3] =>
  string(12) "akjflsdafacd"
  [4] =>
  string(12) "cdakjflsdafa"
  [5] =>
  string(12) "dafacdakjfls"
  [6] =>
  string(12) "dakjflsdafac"
  [7] =>
  string(12) "facdakjflsda"
  [8] =>
  string(12) "flsdafacdakj"
  [9] =>
  string(12) "jflsdafacdak"
  [10] =>
  string(12) "kjflsdafacda"
  [11] =>
  string(12) "lsdafacdakjf"
  [12] =>
  string(12) "sdafacdakjfl"
}

输出完成 (耗时 0 秒) - 正常终止

你看是否符合你的要求~~~