53. Maximum Subarray Problem Given an integer array nums, find the subarray with the largest sum, and return its sum. A subarray is a contiguous ... 2025-01-08 medium
661. Image Smoother Problem An image smoother is a filter of the size 3 x 3 that can be applied to each cell of an image by rounding down the ave... 2024-11-18 easy
435. Non-overlapping Intervals Problem Given an array of intervals intervals where intervals[i] = [startᵢ, endᵢ], return the minimum number of intervals you... 2024-11-18 medium
49. Group Anagrams Problem Given an array of strings strs, group the anagrams together. You can return the answer in any order. An Anagram is a... 2024-11-17 medium
48. Rotate Image Problem You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). You have to rotat... 2024-11-17 medium
825. Friends Of Appropriate Ages Problem There are n persons on a social media website. You are given an integer array ages where ages[i] is the age of the iᵗ... 2024-11-17 medium
300. Longest Increasing Subsequence Problem Given an integer array nums, return the length of the longest strictly increasing subsequence. A subsequence is an a... 2024-11-17 medium hard
297. Serialize and Deserialize Binary Tree Problem Serialization is the process of converting a data structure or object into a sequence of bits so that it can be store... 2024-11-16 hard
424. Longest Repeating Character Replacement Problem You are given a string s and an integer k. You can choose any character of the string and change it to any other uppe... 2024-11-16 medium
295. Find Median from Data Stream Problem The median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value,... 2024-11-16 hard
3240. Minimum Number of Flips to Make Binary Grid Palindromic II Problem You are given an m x n binary matrix grid. A row or column is considered palindromic if its values read the same forw... 2024-11-16 medium
417. Pacific Atlantic Water Flow Problem There is an m x n rectangular island that borders both the Pacific Ocean and Atlantic Ocean. The Pacific Ocean touche... 2024-11-16 medium
33. Search in Rotated Sorted Array Problem There is an integer array nums sorted in ascending order (with distinct values). Prior to being passed to your functi... 2024-11-15 medium
153. Find Minimum in Rotated Sorted Array Problem Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums ... 2024-11-15 medium
3239. Minimum Number of Flips to Make Binary Grid Palindromic I Problem You are given an m x n binary matrix grid. A row or column is considered palindromic if its values read the same forw... 2024-11-15 medium
152. Maximum Product Subarray Problem Given an integer array nums, find a subarray that has the largest product, and return the product. A subarray is a c... 2024-11-15 medium
23. Merge k Sorted Lists Problem You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-l... 2024-11-14 hard
21. Merge Two Sorted Lists Problem You are given the heads of two sorted linked lists list1 and list2. Merge the two lists into one sorted list. The lis... 2024-11-14 easy
20. Valid Parentheses Problem Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is val... 2024-11-14 easy
19. Remove Nth Node From End of List Problem Given the head of a linked list, remove the nᵗʰ node from the end of the list and return its head. https://leetcode.c... 2024-11-14 medium
143. Reorder List Problem You are given the head of a singly linked-list. The list can be represented as: L0 → L1 → … → Ln - 1 → Ln Reorder t... 2024-11-14 medium
3249. Count the Number of Good Nodes Problem There is an undirected tree with n nodes labeled from 0 to n - 1, and rooted at node 0. You are given a 2D integer ar... 2024-11-14 medium
3261. Count Substrings That Satisfy K-Constraint II Problem You are given a binary string s and an integer k. You are also given a 2D integer array queries, where queries[i] = [... 2024-11-13 hard
15. 3Sum Problem Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k... 2024-11-13 medium
268. Missing Number Problem Given an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is mi... 2024-11-12 easy
141. Linked List Cycle Problem Given head, the head of a linked list, determine if the linked list has a cycle in it. There is a cycle in a linked l... 2024-11-12 easy
3258. Count Substrings That Satisfy K-Constraint I Problem You are given a binary string s and an integer k. A binary string satisfies the k-constraint if either of the followi... 2024-11-12 easy
139. Word Break Problem Given a string s and a dictionary of strings wordDict, return true if s can be segmented into a space-separated seque... 2024-11-11 medium
1547. Minimum Cost to Cut a Stick Problem Given a wooden stick of length n units. The stick is labelled from 0 to n. For example, a stick of length 6 is labell... 2024-11-11 hard
11. Container With Most Water Problem You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of th... 2024-11-11 medium
647. Palindromic Substrings Problem Given a string s, return the number of palindromic substrings in it. A string is a palindrome when it reads the same ... 2024-11-10 medium
133. Clone Graph Problem Given a reference of a node in a connected undirected graph. Return a deep copy (clone) of the graph. Each node in th... 2024-11-10 medium