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...
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...
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...
20. Valid Parentheses
Problem Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input str...
19. Remove Nth Node From End of List
Problem Given the head of a linked list, remove the n^th node from the end of the list and return its head. https://leetcode....
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...
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...
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] = [...
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...
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...
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...
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...
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...
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...
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...
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 ...
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...
5. Longest Palindromic Substring
Problem Given a string s, return the longest palindromic substring in s. A string is palindromic if it reads the same forwar...
540. Single Element in a Sorted Array
Problem You are given a sorted array consisting of only integers where every element appears exactly twice, except for one el...
3. Longest Substring Without Repeating Characters
Problem Given a string s, find the length of the longest substring without repeating characters. A substring is a contiguous...
3242. Design Neighbor Sum Service
Problem You are given a n x n 2D array grid containing distinct elements in the range [0, n^2 - 1]. Implement the NeighborSum...
1. Two Sum
Problem Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to tar...
128. Longest Consecutive Sequence
Problem Given an unsorted array of integers nums, return the length of the longest consecutive elements sequence. You must wr...
3235. Check if the Rectangle Corner Is Reachable
Problem You are given two positive integers xCorner and yCorner, and a 2D array circles, where circles[i] = [x_i, y_i, r_i] d...