Tree Depth Sum

Given a binary tree, write a function to compute the sum of all node values multiplied by their depth. The depth of the root is 0, the depth of the root's children is 1, and so on. Input format: The first line contains an integer N, the number of nodes in the tree. The next N lines contain three integers: the node value, the left child value, and the right child value, where -1 indicates that the child does not exist. Output format: Output a single integer representing the total weighted sum of nodes. Example: Input: 3 1 2 3 2 -1 -1 3 -1 -1 Output: 3