Minimum Window Substring Match

Problem

Given two strings s and t, return the shortest substring of s that contains every character in t, including duplicates. If no such substring exists, return an empty string. The input is two strings, and the output is a string.

Constraints

• 1 <= len(s) <= 10^5
• 1 <= len(t) <= 10^5
• s and t consist of English letters
• Duplicates in t must be matched in the window