### Problem: Diameter of Binary Tree #### Problem Statement Given the root of a binary tree, return the length of the **diameter** of the tree. The diameter of a tree is the largest number of nodes on a longest path between any two leaf nodes. #### Rules and Constraints - The tree will not be empty. - Each node of the tree will contain an integer value, but this value is not relevant for this problem. - You can assume that the tree has been constructed with the following properties: - Each node can have at most 2 children (left child and right child). - We can assume that the tree is a binary tree, i.e., it can be traversed with a tree traversal algorithm. #### Assumptions and Validations - You may assume that the function should perform a traversal of the tree to calculate the diameter. - Nodes that have only one child can be considered leaf nodes if there are no further children on that path. - Nodes with multiple children that have no value may be considered to have children as long as there is a child node attached to them. #### Return Value The function should return an integer representing the length of the diameter of the binary tree. #### Time and Space Complexity The function's time complexity should be O(n), where n is the total number of nodes in the tree, assuming that the tree can be traversed once. The space complexity should be O(log n) in the case of an extremely skewed tree (essentially a linked list) and up to O(n) in the case of a balanced tree, due to potential recursive function call stack overflow. ### Example **Input:** {"root":[1,2,3,4,5]} **Output:** 3