Stacks and Queues · Coding problem
Valid Parentheses
A free coding problem from the Stack Matching Validation skill. Read it here, then solve it in the app in Java or Python.
- Easy
- Coding problem
- Free
- Java and Python
The problem
Check whether the brackets in s are properly matched. s uses only the characters ( ) [ ] { }. Every opening bracket needs a closing bracket of the same kind, and pairs must nest: whatever opens last closes first.
Example
Input: s = "{[()()]}"
Output: true
Input: s = "[(])"
Output: false
In the second, the ( is still open when the ] arrives.
Constraints
1 <= s.length <= 2 * 10^5sconsists only of the characters()[]{}
How it's graded
- Run checks your code against the examples. Submit also runs a hidden suite in four groups - basic cases, edge cases, random inputs and performance tests at the size limit - and shows which groups pass, never the hidden inputs.
- Stuck? Hints come in four steps, from a nudge to a code skeleton, each costing part of the points.
- Once you pass, you see the approaches from brute force to optimal, and where your solution lands among them.
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