Given the root of a Binary Search Tree (BST), convert it into a Greater Tree where every node’s value is replaced by the sum of all greater node values in the BST plus its original value.
Given the root of a binary tree, return the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes, which may or may not pass through the root.
Given the roots of two binary trees, root and subRoot, return true if there is a subtree of root with the same structure and node values of subRoot and false otherwise. A subtree of a binary tree consists of a node in the tree and all of this node’s descendants.
Given the root of an n-ary tree, return the preorder traversal of its nodes’ values. In one step, the node is visited first, followed by its children from left to right. The input is serialized in a level order format where each group of children is separated by a null value.
