Minimum Window Substring
Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string "".
The testcases will be generated such that the answer is unique.
Example 1
Input
s = "ADOBECODEBANC", t = "ABC"Output
"BANC"The minimum window substring "BANC" includes 'A', 'B', and 'C' from string t.
Example 2
Input
s = "a", t = "a"Output
"a"Both 'a's from t must be included in the window.
Since the largest window of s only has one 'a', return empty string.
Constraints
- m == s.length
- n == t.length
- 1 <= m, n <= 10^5
sandtconsist of uppercase and lowercase English letters.