Valid Parentheses
Description
Given a string s
containing just the characters '('
, ')'
, '{'
, '}'
, '['
and ']'
, determine if the input string is valid.
An input string is valid if:
- Open brackets must be closed by the same type of brackets.
- Open brackets must be closed in the correct order.
Example 1:
Input: s = "()" Output: true
Example 2:
Input: s = "()[]{}" Output: true
Example 3:
Input: s = "(]" Output: false
Constraints:
1 <= s.length <= 104
s
consists of parentheses only'()[]{}'
.
Solution(javascript)
/**
* @param {string} s
* @return {boolean}
*/
var isValid = function(s) {
let hash = {"(":")", "{":"}", "[":"]"};
let stack = [];
for (let i = 0; i < s.length; i++) {
if(hash[s[i]]) {
stack.push(s[i])
} else {
if (stack.length == 0) {
return false;
}
let open = stack.pop();
if (hash[open] != s[i]) {
return false;
}
}
}
return stack.length === 0;
};