我正在尝试 LeetCode 中的一个问题，看起来快完成了。这就是我到目前为止所做的：和问题链接 – 。以下是我到目前为止所做的代码片段：

static IList < int > FindSubstring(string s, string[] words) {
    var list = new List < IList < string >> ();
    DoPermutation(words, 0, words.Length - 1, list);

    return TrackIndexes(s, list);
  }

  static IList < IList < string >> DoPermutation(string[] str, int start, int end, IList < IList < string >> list) {
    if (start == end) {
      list.Add(new List < string > (str));
    } else {
      for (var i = start; i <= end; i++) {
        Swap(ref str[start], ref str[i]);

        DoPermutation(str, start + 1, end, list);

        Swap(ref str[start], ref str[i]);
      }
    }

    return list;
  }

  static void Swap(ref string a, ref string b) {
    var temp = a;
    a = b;
    b = temp;
  }

  static List < int > TrackIndexes(string pattern, IList < IList < string >> aLst) {
    int count = 0;

    List < string > strings;
    List < int > indexes = new List < int > ();

    foreach(var item in aLst) {
      string str = "";

      strings = new List < string > {
        String.Concat(item)
      };

      foreach(var list in item) {
        str += list;

        if (str.Length == strings[0].Length && pattern.Contains(str)) {
          indexes.AddRange(AllIndexesOf(pattern, str));
          count += 1;
        }
      }
    }

    indexes.Sort();
    return indexes.Distinct().ToList();
  }

public static int[] AllIndexesOf(string str, string substr, bool ignoreCase = false) 
{
  if (string.IsNullOrWhiteSpace(str) || string.IsNullOrWhiteSpace(substr)) 
  {
    throw new ArgumentException("String or substring is not specified.");
  }

  var indexes = new List<int>();
  int index = 0;

  while ((index = str.IndexOf(substr, index, ignoreCase ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal)) != -1) 
  {
    indexes.Add(index++);
  }

  return indexes.ToArray();
}

我遇到的问题是以下输入：

s = "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", 

words = ["dhvf","sind","ffsl","yekr","zwzq","kpeo","cila","tfty","modg","ztjg","ybty","heqg","cpwo","gdcj","lnle","sefg","vimw","bxcb"]

我的代码在方法中创建了一个可能的排列列表DoPermutation，对于上述输入，它生成了一个出现内存不足错误的字符串列表。我不确定是否可以使用我拥有的代码片段来更改任何内容。

目前，我的代码通过了 180 个测试用例中的 151 个。无论如何，是否使用现有的代码片段来消除内存异常，或者我必须重新考虑该问题？

目标：代码的主要目标是为字符串列表创建可能的排列，并将模式中的这些字符串作为子字符串进行匹配。