代码public class Solution { public int LengthOfLongestSubstring(string s) { int left, result; HashSetchar chars new HashSetchar(); left result 0; for (int right 0; right s.Length; right) { while (chars.Contains(s[right])) { chars.Remove(s[left]); left; } chars.Add(s[right]); result Math.Max(result, right - left 1); } return result; } }结果