Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview.

Enhance your coding abilities and get valuable real-world feedback by participating in contests on LeetCode. You can also win up to 5000 LeetCoins per contest, as well as bonus prizes from …

Enhance your coding skills and prepare for job interviews with LeetCode's study plans.

Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview.

You are given the head of a linked list, and an integer k. Return the head of the linked list after swapping the values of the k th node from the beginning and the k th node from the end (the list is 1-indexed). …

Can you solve this real interview question? Time Needed to Buy Tickets - There are n people in a line queuing to buy tickets, where the 0th person is at the front of the line and the (n - 1)th person is at …

Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview.

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Nov 20, 2025 · Join LeetCode Discuss for coding insights, learning opportunities, and networking with fellow programmers in a vibrant community.

Can you solve this real interview question? Valid Parentheses - Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: 1. Open …