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 …

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 …

Can you solve this real interview question? Minimum Window Substring - Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every …

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.

Can you solve this real interview question? Best Time to Buy and Sell Stock II - You are given an integer array prices where prices[i] is the price of a given stock on the ith day. On each day, …

Can you solve this real interview question? Word Break - Given a string s and a dictionary of strings wordDict, return true if s can be segmented into a space-separated sequence of one or …

Can you solve this real interview question? Subarray Sum Equals K - Given an array of integers nums and an integer k, return the total number of subarrays whose sum equals to k. A …

Can you solve this real interview question? Missing Number - Given an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is missing from …

Given the root of a binary tree, return the level order traversal of its nodes' values. (i.e., from left to right, level by level). Example 1: Input: root = [3,9,20 ...