Diameter of a Tree

Calculate the diameter of a binary tree. The diameter is defined as the length of the longest path between any two nodes in the tree, which may or may not pass through the root. Input format: - The first line contains an integer N, the number of nodes in the tree. - The following N lines contain integers representing each node's value in level-order traversal. Use -1 to indicate 'null' nodes. Output format: - Print a single integer representing the diameter of the tree. Example: Input: 5 1 2 3 -1 -1 4 -1 -1 Output: 3