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Valid Parentheses

easy

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.

Test Cases

Copy an input into the main harness and Run to verify
Input
s = "()"
Expected Output
true
Input
s = "()[]{}"
Expected Output
true
Input
s = "(]"
Expected Output
false

Constraints

  • 1 <= s.length <= 10^4
  • s consists of parentheses only '()[]{}'.

Hints

Hint 1 — click to reveal

Push opening brackets; pop and match on closing ones.

Hint 2 — click to reveal

If the stack is not empty at the end, something was never closed.

Java Compiler

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