Link to problem Problem Given two integer arrays inorder and postorder where inorder is the inorder traversal of a binary tree and postorder is the postorder traversal of the same tree, construct...

Link to problem Problem Given the root of a binary tree, return the postorder traversal of its nodes’ values. Solution Simple post order traversal problem. Could be solved with trivial recursiv...

Link to problem Problem Given two integer arrays pushed and popped each with distinct values, return true if this could have been the result of a sequence of push and pop operations on an initial...

Link to problem Problem Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. ...

Link to problem Problem Given the root of a binary tree, find the maximum value v for which there exist different nodes a and b where v = |a.val - b.val| and a is an ancestor of b. A node a is a...

Link to problem Problem You are given an integer n indicating there are n people numbered from 0 to n - 1. You are also given a 0-indexed 2D integer array meetings where meetings[i] = [x_i, y_i, ...

Link to problem Problem You are given an m x n integer matrix points (0-indexed). Starting with 0 points, you want to maximize the number of points you can get from the matrix. To gain points, y...

Link to problem Problem Given a binary tree rootand a linked list with head as the first node. Return True if all the elements in the linked list starting from the head correspond to some downwa...

Link to problem Problem Given a sentence text (A sentence is a string of space-separated words) in the following format: First letter is in upper case. Each word in text are separated by a ...

Link to problem Problem A wiggle sequence is a sequence where the differences between successive numbers strictly alternate between positive and negative. The first difference (if one exists) may...