Minimum Window Substring

The Problem 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 "". A substring is a contiguous, non-empty sequence of characters within a string. The test cases will be generated such that the answer is unique. Examples Input: s = "ADOBECODEBANC", t = "ABC" Output: "BANC" Explanation: The minimum window substring "BANC" includes 'A', 'B', and 'C' from string t. Input: s = "a", t = "a" Output: "a" Explanation: The entire string s is the minimum window. Input: s = "a", t = "aa" Output: "" Explanation: Both 'a's from t must be included in the window. Since the largest window of s only has one 'a', return an empty string. Constraints m == s.length n == t.length 1 <= m, n <= 10⁵ s and t consist of uppercase and lowercase English letters. Follow-up: Could you find an algorithm that runs in O(m + n) time? ...