Valid Parentheses
Updated Jan 31, 2026
Problem
Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
An input string is valid if:
1. Open brackets must be closed by the same type of brackets.
2. Open brackets must be closed in the correct order.
3. Every close bracket has a corresponding open bracket of the same type.
Constraints
1 <= s.length <= 10^4
s consists of parentheses only '()[]{}'.
Examples
Example 1
Input:
s = "()"
Output:
true
Example 2
Input:
s = "()[]{}"
Output:
true
Example 3
Input:
s = "(]"
Output:
false
Function Signature
def isValid(self, s: str) -> bool
How to Submit
Implement a Solution class with a isValid method.
Your method will be called with the input parameters and should return the answer.