In this video, we solve LeetCode Problem #20 — Valid Parentheses.
You’ll learn:
How stacks work
Matching brackets efficiently
Optimized O(n) solution
Step-by-step dry run
Common interview edge cases
Problem Statement:
Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
A string is valid if:
Open brackets are closed by the same type
Open brackets are closed in the correct order
Example:
Input: s = "()[]{}"
Output: true
Input: s = "(]"
Output: false
Topics Covered:
Stack Data Structure
String Processing
Interview Problem Solving
Time & Space Complexity
