20.js

/** ------------------------------------------------------------------------------
 * 
 * 2023-04-10
 * Valid Parentheses
 * https://leetcode.com/problems/valid-parentheses/
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {string} s
 * @return {boolean}
 */
var isValid = function (s) {
  const stack = [];

  for (const p of s) {
    if (p === ")") {
      if (stack[stack.length - 1] !== "(") return false;
      stack.pop();
    } else if (p === "}") {
      if (stack[stack.length - 1] !== "{") return false;
      stack.pop();
    } else if (p === "]") {
      if (stack[stack.length - 1] !== "[") return false;
      stack.pop();
    } else {
      stack.push(p);
    }
  }

  return stack.length === 0;
};