202407141234
tags: #sliding-window

var minWindow = function(s, t) {
	const map = new Map();
	for (const c of t) {
		map.set(c, (map.get(c) ?? 0) + 1);
	}
	let start = 0;
	let counter = 0;
	let minLen = Number.POSITIVE_INFINITY;
	let minStart = -1;
	for (let end = 0; end < s.length; end++) {
		map.set(s[end], (map.get(s[end]) ?? 0) - 1);
		if (map.get(s[end]) >= 0) {
			counter += 1;
		}
		while (counter === t.length) {
			if (end - start + 1 < minLen) {
				minLen = end - start + 1;
				minStart = start;
			}
			map.set(s[start], map.get(s[start]) + 1);
			if (map.get(s[start]) > 0) {
				counter -= 1;
			}
			start += 1;
		}
	}
	return minLen === Number.POSITIVE_INFINITY ? "" : s.substring(minStart, minStart + minLen);
};

Reference

https://leetcode.com/problems/minimum-window-substring/