Loading the journal
Day 10Easy
LeetCodeRelated practice
LeetCodeRelated practiceValid Parentheses
Stack / Hash Map LookupSolved Nov 7, 2025
Loading the journal
LeetCodeRelated practiceStack / Hash Map LookupSolved Nov 7, 2025
12 in the last 6 months
Community-reported company tags from leetcode-company-wise-problems (updated 2026-10-08). Bar shows how often each company asks it.
Problem
Given a string S containing only the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. A valid string requires opening brackets to be closed by the same type of bracket and in the correct order.
Reading the solution first feels like progress, but it makes the next similar problem — and the interview version — much harder, because you skipped the part where you figure it out. Give it an honest 20–30 minutes. Stuck? Re-read the pattern, watch the concept video, or try the brute force first.
Hidden: approach · step-by-step visual · solution code
Watch walkthrough