Valid Parentheses – LeetCode 20 Explained Simply
LeetCode · Problem 20 · Easy Valid Parentheses – LeetCode 20 Explained Simply A beginner-friendly guide to checking bracket order with a Stack, including examples, visual explanation, a complete dry run, and fully commented Python, Java and PHP solutions. Stack String DSA Interview Preparation Table of Contents Introduction Problem Statement Examples Explained Understanding the Problem Important Concepts Optimal Approach Visual Explanation Complete Dry Run Pseudocode Python, Java and PHP Code Complexity Analysis Edge Cases Common Mistakes Interview Preparation FAQs Conclusion 1. Introduction Brackets are used everywhere in programming. They group instructions, define functions, access array elements and help describe mathematical expressions. But brackets must be opened and closed in the correct order. For example, () is correct, while (] is not. The Valid Parentheses problem asks us to check whether a string containing round brackets () , curly brackets {} ...
