20.有效的括号

/*
 * @lc app=leetcode.cn id=20 lang=typescript
 *
 * [20] 有效的括号
 */

// @lc code=start
interface mapKey {
	[key: string]: string;
}
function isValid(s: string): boolean {
	const stack: string[] = [];
	const map: mapKey = {
		"(": ")",
		"[": "]",
		"{": "}"
	};

	for (let i = 0; i < s.length; i++) {
		const char = s[i];
		if (["(", "[", "{"].includes(char)) {
			stack.push(char);
		} else {
			const top = stack.pop() || ""; // 取出数组中最后一项

			if (char != map[top]) {
				return false;
			}
		}
	}

	return stack.length === 0;
}

console.log(isValid('([)]'));

// @lc code=end