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有效的括号

2022/08/01

https://leetcode.cn/problems/valid-parentheses/

示例​

示例一​

输入：s = "()"
输出：true

示例二​

输入：s = "()[]{}"
输出：true

示例三​

输入：s = "(]"
输出：false

示例四​

输入：s = "([)]"
输出：false

示例五​

输入：s = "{[]}"
输出：true

题解参考​

栈​

var isValid = function (s) {
  const len = s.length;
  if (len % 2 === 1) {
    return false;
  }
  const pairs = new Map([
    [")", "("],
    ["]", "["],
    ["}", "{"],
  ]);
  const stack = [];
  for (let char of s) {
    if (pairs.has(char)) {
      if (!stack.length || stack[stack.length - 1] !== pairs.get(char)) {
        return false;
      }
      stack.pop();
    } else {
      stack.push(char);
    }
  }

  return !stack.length
};