443. String Compression Problem Given an array of characters chars, compress it using the following algorithm: Begin with an empty string s. For each... 2024-11-27 medium
3255. Find the Power of K-Size Subarrays II 跟 3254. Find the Power of K-Size Subarrays I 一模一样,只不过 n 的上限从 500 增加到 10⁵。 https://leetcode.cn/problems/find-the-power-of-k-si... 2024-11-27 medium
3254. Find the Power of K-Size Subarrays I Problem You are given an array of integers nums of length n and a positive integer k. The power of an array is defined as: I... 2024-11-27 medium
633. Sum of Square Numbers Problem Given a non-negative integer c, decide whether there’re two integers a and b such that a² + b² = c. https://leetcode.... 2024-11-27 medium
3208. Alternating Groups II Problem There is a circle of red and blue tiles. You are given an array of integers colors and an integer k. The color of til... 2024-11-27 medium
638. Shopping Offers Problem In LeetCode Store, there are n items to sell. Each item has a price. However, there are some special offers, and a sp... 2024-11-27 medium
3259. Maximum Energy Boost From Two Drinks Problem You are given two integer arrays energyDrinkA and energyDrinkB of the same length n by a futuristic sports scientist.... 2024-11-26 medium
2924. Find Champion II Problem There are n teams numbered from 0 to n - 1 in a tournament; each team is also a node in a DAG. You are given the inte... 2024-11-26 medium
371. Sum of Two Integers Problem Given two integers a and b, return the sum of the two integers without using the operators + and -. https://leetcode.... 2024-11-25 medium
743. Network Delay Time Problem You are given a network of n nodes, labeled from 1 to n. You are also given times, a list of travel times as directed... 2024-11-28 medium
238. Product of Array Except Self Problem Given an integer array nums, return an array answer such that answer[i] is equal to the product of all the elements o... 2024-11-24 medium
235. Lowest Common Ancestor of a Binary Search Tree Problem Given a binary search tree (BST), find the lowest common ancestor (LCA) node of two given nodes in the BST. According... 2024-11-24 medium
377. Combination Sum IV Problem Given an array of distinct integers nums and a target integer target, return the number of possible combinations that... 2024-11-24 medium
105. Construct Binary Tree from Preorder and Inorder Traversal Problem Given two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder i... 2024-11-24 medium
230. Kth Smallest Element in a BST Problem Given the root of a binary search tree, and an integer k, return the kᵗʰ smallest value (1-indexed) of all the values... 2024-11-23 medium
102. Binary Tree Level Order Traversal Problem Given the root of a binary tree, return the level order traversal of its nodes’ values. (i.e., from left to right, le... 2024-11-23 medium
1143. Longest Common Subsequence Problem Given two strings text1 and text2, return the length of their longest common subsequence. If there is no common subse... 2024-11-23 medium
98. Validate Binary Search Tree Problem Given the root of a binary tree, determine if it is a valid binary search tree (BST). A valid BST is defined as follo... 2024-11-23 medium
347. Top K Frequent Elements Problem Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any o... 2024-11-23 medium
91. Decode Ways Problem You have intercepted a secret message encoded as a string of numbers. The message is decoded via the following mappin... 2024-11-23 medium
213. House Robber II Problem You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed... 2024-11-23 medium
211. Design Add and Search Words Data Structure Problem Design a data structure that supports adding new words and finding if a string matches any previously added string. I... 2024-11-22 medium
208. Implement Trie (Prefix Tree) Problem A trie (pronounced as “try”) or prefix tree is a tree data structure used to efficiently store and retrieve keys in a... 2024-11-22 medium
207. Course Schedule Problem There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array pr... 2024-11-22 medium
3233. Find the Count of Numbers Which Are Not Special Problem You are given 2 positive integers l and r. For any number x, all positive divisors of x except x are called the prope... 2024-11-22 medium
79. Word Search Problem Given an m x n grid of characters board and a string word, return true if word exists in the grid. The word can be co... 2024-11-21 medium
73. Set Matrix Zeroes Problem Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0’s. You must do it in pla... 2024-11-21 medium
200. Number of Islands Problem Given an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islan... 2024-11-21 medium
198. House Robber Problem You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed... 2024-11-20 medium
322. Coin Change Problem You are given an integer array coins representing coins of different denominations and an integer amount representing... 2024-11-19 medium
3243. Shortest Distance After Road Addition Queries I Problem You are given an integer n and a 2D integer array queries. There are n cities numbered from 0 to n - 1. Initially, th... 2024-11-19 medium
62. Unique Paths Problem There is a robot on an m x n grid. The robot is initially located at the top-left corner (i.e., grid[0][0]). The robo... 2024-11-19 medium