Day 27 — Daily JavaScript Algorithm

Valid Parentheses Checker

Welcome to Day 27 of our Daily JavaScript Algorithm series! Today, we’ll solve the Valid Parentheses problem, an essential question in stack-based algorithms and coding interviews.

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Problem Statement

Given a string s containing only the characters (, ), {, }, [ and ], determine if the input string is valid.

A string is valid if:

1. Open brackets are closed by the same type of brackets.
2. Open brackets are closed in the correct order.
3. Every close bracket has a corresponding open bracket of the same type.

Example 1:

• Input: s = "()"
• Output: true

Example 2:

• Input: s = "()[]{}"
• Output: true

Example 3:

• Input: s = "(]"
• Output: false

Example 4:

• Input: s = "{[()]}"
• Output: true

Example 5:

• Input: s = "{[(])}"