CodingHardcod-g319

Subject Sliding windowLevel Senior–Staff~35 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given strings s and t, return the shortest substring of s that contains every character of t including multiplicities. If no such substring exists, return the empty string. If multiple shortest windows exist, return the one that starts earliest. Constraints: 1 <= len(s), len(t) <= 10^4, both consist of uppercase and lowercase English letters.

Implement

min_window_substring(s: str, t: str) → str

Examples

in["ADOBECODEBANC","ABC"]out"BANC"

What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Learn the concepts

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.