solution.h

/*
Code generated by https://github.com/goodstudyqaq/leetcode-local-tester
*/
#if __has_include("../utils/cpp/help.hpp")
#include "../utils/cpp/help.hpp"
#elif __has_include("../../utils/cpp/help.hpp")
#include "../../utils/cpp/help.hpp"
#else
#define debug(...) 42
#endif

class Solution {
   public:
    string minWindow(string s, string t) {
        unordered_map<char, int> M;
        unordered_set<char> S;
        for (auto it : t) {
            M[it]++;
            S.insert(it);
        }
        int r = 0;
        int n = s.size();
        int ans = n + 1;
        int idxl = -1, idxr = -1;
        int now_score = 0;
        for (int i = 0; i < n; i++) {
            while (r < n && now_score < S.size()) {
                char it = s[r];
                if (S.count(it)) {
                    M[it]--;
                    if (M[it] == 0) {
                        now_score++;
                    }
                }
                r++;
            }
            if (now_score < S.size()) break;
            if (ans > r - i) {
                ans = r - i;
                idxl = i;
                idxr = r;
            }
            char it = s[i];
            if (S.count(it)) {
                M[it]++;
                if (M[it] > 0) {
                    now_score--;
                }
            }
        }
        if (ans == n + 1) return "";
        string res = s.substr(idxl, idxr - idxl);
        return res;
    }
};