78. Subsets Problem Given an integer array nums of unique elements, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any o...

46. Permutations Problem Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order. Questions before reading example Example Inpu...

429. N-ary Tree Level Order Traversal Problem Given an n-ary tree, return the level order traversal of its nodes' values. Nary-Tree input serialization is represented in their level order traver...

206. ReverseLinkedList Problem Given the head of a singly linked list, reverse the list, and return the reversed list. Questions before reading example Example Input: head = [1,2,3,4,5] Outp...

412. Fizz Buzz Problem Given an integer n, return a string array answer (1-indexed) where: answer[i] == "FizzBuzz" if i is divisible by 3 and 5. answer[i] == "Fizz" if i is divisible by 3. answe...

136. Single Number Problem Given a non-empty array of integers nums, every element appears twice except for one. Find that single one. You must implement a solution with a linear runtime complex...

344. Reverse String Problem Write a function that reverses a string. The input string is given as an array of characters s. You must do this by modifying the input array in-place with O(1) extra...

104. Maximum Depth Of Binary Tree Problem Given the root of a binary tree, return its maximum depth. A binary tree's maximum depth is the number of nodes along the longest path from the root nod...

7. Reverse Integer Problem Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then ...

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 target. You may assume that each input would have exactly one ...