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