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.

Examples

Example 1:

Input: s = "ADOBECODEBANC", t = "ABC"
Output: "BANC"

Example 2:

Input: s = "a", t = "a"
Output: "a"

Example 3:

Input: s = "a", t = "aa"
Output: ""

Constraints

• m == s.length
• n == t.length
• 1 <= m, n <= 10^5
• s and t consist of uppercase and lowercase English letters