20180817 七颗葡萄汇聚

[ShaofeiZi]

LeetCode 20题 Valid Parentheses
给一个字符串，包括'(', ')', '{', '}', '[' 和‘]’ 判断是否是正确组成顺序，例如“()”和“(){}[]”是正确的，但是“(]”和"([)]"错误。

[KingJeason]

/**
 * @param {string} s
 * @return {boolean}
 */
var isValid = function(s) {
        let map = {
        ')': '(',
        ']': '[',
        '}': '{'
    }
    let stack = []
    for (let i = 0; i < s.length; i++) {
        let c = s[i]
        if (c === '(' || c === '[' || c === '{') {
            stack.push(c)
        } else if (c === ')' || c === ']' || c === '}') {
            if (map[c] === stack[stack.length - 1]) {
                stack.pop()
            } else {
                return false
            }
        }
    }
    return stack.length === 0
}

[liuguangsen0409]

var isValid = function(s) {
    var i,len = s.length,arr=new Array(),arrlen,tmp;
    if(s%2 == 1)
        return false;
    for(i=0;i<len;i++){
        if(s[i] == "(" || s[i] == "[" || s[i] == "{"){
            arr.push(s[i]);
        }else{
            arrlen = arr.length;
            tmp = arr[arrlen - 1];//表示现在的栈顶元素
            if((tmp == "(" && s[i] == ")") || (tmp == "[" && s[i] == "]") || (tmp == "{" && s[i] == "}")){
                arr.pop();
            }else{
                return false;
            }
        }
    }
    if(arr.length == 0){
        return true;
    }else{
        return false;
    }
};

[gp0320]

var isValid = function(s) {
    let patt = /\(\)|\[\]|\{\}/
    let s2 = s.replace(patt,'')
    if(s2 == s){
        return !s2
    }
    return isValid(s2)
};

[chili-kwh]

/**
 * @param {string} str
 * @return {boolean}
 */

const PARENTHESIS_MAP = {
    ')': '(',
    ']': '[',
    '}': '{'
}

function isValid(str) {
    let stack = [];
    for (let e of str) {
        switch (e) {
            case ('('): case ('{'): case ('['):
                stack.push(e);
                break;

            case (')'): case ('}'): case (']'):
                if (PARENTHESIS_MAP[e] !== stack.pop()) return false;
                break;

            default:
                break;
        }
    }
    return !stack.length;
}

isValid('[]][');
`