leetcode

0 class Solution {

1 public:

2 string minWindow(string s, string t) {

3 vector<int> remaining(128, 0);

4 for (char c : t)

5 remaining[c]++;

6

7 int required = t.size();

8 int min = INT_MAX, start = 0, left = 0, i = 0;

9 while (i <= s.size() && start < s.size()) {

10 if (required) {

11 if (i == s.size()) break;

12 if (--remaining[s[i++]] >= 0) required--;

13 } else {

14 if (i - start < min) {

15 min = i - start;

16 left = start;

17 }

18 if (++remaining[s[start++]] > 0) required++;

19 }

20 }

21 return min == INT_MAX ? "" : s.substr(left, min);

22 }

23 };