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.
You are given the root of a binary tree, and two integers val and depth. You need to add a row of nodes with value val at the given depth depth. The root node is considered to be at depth 1.
Given the root of a binary tree, return all duplicate subtrees. For each duplicate subtree, return the root node of any one of them. Two trees are considered duplicates if they have the same structure and node values.
