Longest Substring Without Repeating Characters

题目链接: https://leetcode.com/problems/longest-substring-without-repeating-characters/description/

#include <iostream>
#include <vector>
using namespace std;

int length(string s) {
	vector<int> dict(256,-1);
	int maxLen = 0, start = -1;
	for(int i = 0; i != s.length(); i++) {
		if(dict[s[i]] > start)
			start = dict[s[i]];
		dict[s[i]] = i;
		maxLen = max(maxLen, i -start);
	}
	return maxLen;
}

int main()
{
	cout<<length("abcabcbb")<<endl;
}

Output: 3

个人理解
dict 记录当前字符出现的位置
start 记录当前字符出现的上一次位置
参考自https://leetcode.com/problems/longest-substring-without-repeating-characters/discuss/1737