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.
Given an integer array nums with no duplicates, construct a maximum binary tree by recursively selecting the largest number as the root, and building the left and right subtrees from the elements before and after the largest number.
Given the root of a binary tree, construct a matrix representation of the tree using specific formatting rules to place each node in the appropriate position in the matrix.
