Maximum Depth of N-ary Tree - Solution & Explanation

This approach leverages the recursive nature of trees to calculate the depth. For each node, if it has no children, it is a leaf and has depth 1. Otherwise, recursively calculate the depth of each child and take the maximum depth found among all children, adding 1 for the current node to account for the path to parent.

The function maxDepth is implemented recursively. We check if the root is None and return 0 which indicates an empty tree. If the node has no children, return 1, indicating it is a leaf. For a node with children, recursively calculate the max depth for each child and add 1 to the result to represent the current node.

This approach utilizes BFS using a queue to iteratively compute tree depth. Nodes are enqueued level by level. At each level, we count its nodes, dequeuing them and enqueueing their children, indicating traversing to the next tree level. We increment a level counter as we progress deeper into the tree.

We use a deque to facilitate breadth-first traversal. In each loop iteration, we process all nodes at the current level and enqueue their children. Each iteration over the level represents moving a depth deeper, and we count these iterations to find the final maximum depth.