[LeetCode][0003] Longest Substring Without Repeating Characters

 

 

class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        int left = 0, right = 0, ret = 0;
        unordered_map<char, int> m;
        while(right < s.size()) {
            if(m.find(s[right]) != m.end()) {
                left = max(left, m[s[right]] + 1);
            }
            ret = max(ret, right - left + 1);
            m[s[right]] = right;
            ++right;
        }
        return ret;
    }
};