veet-code/problems/medium/valid-parentheses/solution.py
2026-02-10 19:50:13 +00:00

37 lines
1 KiB
Python

"""
Valid Parentheses
You're building a syntax checker for a code editor. Before running
any code, the editor needs to verify that all brackets are properly
matched and nested. Given a string containing only parentheses,
square brackets, and curly braces, determine if the input is valid.
A string is valid if:
- Open brackets are closed by the same type of bracket
- Open brackets are closed in the correct order
- Every close bracket has a corresponding open bracket
Example 1:
Input: s = "([]){}"
Output: True
Explanation: All brackets are properly matched and nested
Example 2:
Input: s = "([)]"
Output: False
Explanation: The square bracket closes before the parenthesis
Example 3:
Input: s = "{{"
Output: False
Explanation: Opening braces are never closed
Constraints:
- 0 <= len(s) <= 10^4
- s consists only of characters '(){}[]'
"""
def is_valid(s: str) -> bool:
"""Return True if the bracket string is valid, False otherwise."""
pass # Your implementation here