leetcode 3. Longest Substring Without Repeating Characters

最新推荐文章于 2026-01-04 19:40:08 发布

原创最新推荐文章于 2026-01-04 19:40:08 发布 · 361 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#leetcode

数据结构与算法同时被 2 个专栏收录

213 篇文章

订阅专栏

196 篇文章

订阅专栏

本文介绍了一种解决最长无重复字符子串问题的方法。通过使用C++编程语言中的map和vector数据结构来记录字符串中每个字符出现的位置，并实现了一个算法来找出给定字符串中最长的不包含重复字符的子串长度。

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest substring is "b", with the length of 1.

class Solution {
public:
	int lengthOfLongestSubstring(string s) {
		int k = 0;
		int maxlen = 0;
		map<char, vector<int>>cnt;
		vector<char>aa;
		while (k-aa.size() < s.length()-maxlen)
		{
			int kk = k;
			while (kk < s.length())
			{
				cnt[s[kk]].push_back(kk);
				if (cnt[s[kk]].size() == 2)
					break;
				aa.push_back(s[kk]);
				kk++;
			}
			if (aa.size()>maxlen)
				maxlen = aa.size();
			if (kk == s.length())
				break;
			int index = find(aa.begin(), aa.end(), s[kk]) - aa.begin();
			for (int i = 0; i <= index; i++)
				cnt.erase(cnt.find(aa[i]));
			aa.erase(aa.begin(), aa.begin() + index + 1);
			k = kk;
		}
		return maxlen;
	}
};

accepted