3.无重复字符的最长子串

🥛set  

class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        set<char> st;
        int mx = 0;
        for(int i = 0; i < s.size();) {
            if(st.count(s[i]) > 0) {
                if(st.size()) {
                    st.erase(s[i - st.size()]);
                }
            } else {
                st.insert(s[i]);
                ++i;
            }
            mx = max(mx, (int)st.size());
        }
        return mx;
    }
};

Accepted

987/987 cases passed (48 ms)

Your runtime beats 25.3 % of cpp submissions

Your memory usage beats 14.41 % of cpp submissions (16 MB)