20.valid-parentheses.js

/*
 * @lc app=leetcode id=20 lang=javascript
 *
 * [20] Valid Parentheses
 */

// @lc code=start
/**
 * @param {string} s
 * @return {boolean}
 */
var isValid = function(s) {
    const parenObj = {
        "[" : "]",
        "(" : ")",
        "{" : "}"
    };

    const queue = [];
    
    for(let i = 0; i<s.length; i++){
        if(parenObj[s[i]]){
            queue.push(s[i])
        }else{
            if(parenObj[queue.pop()] !== s[i]){
                return false;
            }
        }
    }
    return queue.length === 0 ? true:false;
};

isValid("[")
// @lc code=end


































/*
let bracketObj = {
        "(": ")",
        "[": "]",
        "{": "}"
    }
   
    let stack = [];
    for(let i = 0; i<s.length; i++){
        if(Object.keys(bracketObj).includes(s[i])){
            stack.push(s[i])
        }
        if(Object.values(bracketObj).includes(s[i])){
            if(bracketObj[stack.pop()] !== s[i]){
                return false
            }
        }
    }
    return stack.length === 0 ? true : false;
*/