这个算法的复杂度是多少?-Whatisthecomplexity(Big-O)ofthisalgorithm?

I'm fairly familiar with algorithm analysis and can tell the Big-O of most algorithms I work with. But I've been stuck for hours unable to come up with the Big-O for this code I write.

我对算法分析相当熟悉，可以告诉我所使用的大多数算法的大o。但是我已经被困了好几个小时，无法为我写的这段代码写出大o。

Basically it's a method to generate permutations for a string. It works by making each character in the string the first character and combine it with the permutations of the substring less that character (recursively).

基本上它是为字符串生成排列的方法。它的工作原理是将字符串中的每个字符作为第一个字符，并将其与子字符串的排列组合(递归地)组合起来。

If I put in the code to count the number of iterations, I've got something between O(N!) and O(N^N). But I couldn't figure out how to analyse it mentally. Any suggestion is much appreciated!

如果我把代码中计算的迭代次数,我有事在O(N)和O(N ^ N)。但我不知道如何在心理上分析它。非常感谢您的建议!

import java.util.ArrayList;
import java.util.List;

public class Permutation {

   int count = 0;

   List findPermutations(String str) {
      List permutatiOns= new ArrayList();
      if (str.length() <= 1) { 
         count++;
         permutations.add(str);
         return permutations;
      }
      for (int i = 0; i 

T(n+1)=(n+1)*(n + T(n) + n!*(n+1))