Problem statement Given the root of a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom. Problem statement taken from: https://leetcode.com/problems/binary-tree-right-side-view Example 1: Input: root = [1, 2, 3, null, 5, null, 4] Output: [1, 3…

Problem statement Given the root of a binary tree and an integer targetSum, return the number of paths where the sum of the values along the path equals targetSum. The path does not need to start or end at the root or a leaf, but it must go downwards (i.e., …

Problem statement You are given the head of a linked list. Remove every node which has a node with a strictly greater value anywhere to the right side of it. Return the head of the modified linked list. Problem statement taken from: https://leetcode.com/problems/remove-nodes-from-linked-list Example 1: Input: head = [5, 2, 13, 3…

Problem statement Given the head of a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x. You should preserve the original relative order of the nodes in each of the two partitions. Problem statement taken from: https://leetcode.com/problems/partition-list …

Problem statement Given an array of positive integers nums and a positive integer target, return the minimal length of a subarray whose sum is greater than or equal to target. If there is no such subarray, return 0 instead. Problem statement taken from: https://leetcode.com/problems/minimum-size-subarray-sum Example 1: Input: target = 7, nums =…

Problem statement Given the root of a binary tree, return the bottom-up level order traversal of its nodes' values. (i.e., from left to right, level by level from leaf to root). Problem statement taken from: https://leetcode.com/problems/binary-tree-level-order-traversal-ii/ Example 1: Input: root = [3, 9, 20, null, null, 15, 7] Output: [[15, 7], [9, 20]…

Problem statement Given an integer array nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. You can return the answer in any order. You must write an algorithm that runs in linear runtime complexity and uses…

Given an unsorted array of integers nums, return the length of the longest consecutive elements sequence. You must write an algorithm that runs in O(n) time. Problem statement taken from: https://leetcode.com/problems/longest-consecutive-sequence Example 1: Input: nums = [100, 4, 200, 1, 3, 2] Output: 4 Explanation: The longest consecutive elements sequence is [1…

Problem statement Given two strings text1 and text2, return the length of their longest common subsequence. If there is no common subsequence, return 0. A subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the…