#LC 20•Stack•Easy
Valid Parentheses
Given a string of brackets, decide whether every opening bracket is closed by the matching bracket in the correct nested order.
Understand the problem
Given a string of brackets, decide whether every opening bracket is closed by the matching bracket in the correct nested order.
Example 1
Input: s = "{[]}"
Output: true
The inner square brackets close first, then the outer curly braces.
Example 2
Input: s = "([)]"
Output: false
The closing parenthesis does not match the latest opening square bracket.
Constraints
- The string contains only (, ), [, ], {, and }.
- The input length is between 1 and 10,000 characters.
Think first
When a closing bracket appears, which opening bracket should it match?
Pattern tags:StackNested pairsEarly mismatch detection