📄️ Add Two Numbers
You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.
📄️ Longest substring without repeating characters
Given a string s, find the length of the longest substring without repeating characters.
📄️ Rotate Image
You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).
📄️ Spiral Matrix
Given an m x n matrix, return all elements of the matrix in spiral order.
📄️ Number of Islands
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 islands.
📄️ Remove starts from string
You are given a string s, which contains stars *.
📄️ Product of Array Except Self
Given an integer array nums, return an array answer such that answer[i] is equal to the product of all the elements of nums except nums[i].
📄️ Container with most water
You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).
📄️ Increasing triplet subsequence
Given an integer array nums, return true if there exists a triple of indices (i, j, k) such that i < j < k and nums[i] < nums[j] < nums[k].
📄️ Decode string
Given an encoded string, return its decoded string.
📄️ Best time to buy & sell stock
You are given an integer array prices where prices[i] is the price of a given stock on the ith day.
📄️ trie
A trie (pronounced as "try") or prefix tree is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. There are various applications of this data structure, such as autocomplete and spellchecker.
📄️ Odd even linked list
Given the head of a singly linked list, group all the nodes with odd indices together followed by the nodes with even indices, and return the reordered list.
📄️ Dota2 Senate
In the world of Dota2, there are two parties: the Radiant and the Dire.
📄️ Delete the middle node of a linked list
You are given the head of a linked list. Delete the middle node, and return the head of the modified linked list.