Problem

Given a n-ary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

For example, given a 3-ary tree:

We should return its max depth, which is 3.

Note:

The depth of the tree is at most 1000.

Solution

/*// Definition for a Node.class Node {    public int val;    public List
    
      children;    public Node() {}    public Node(int _val,List
     
       _children) {        val = _val;        children = _children;    }};*/class Solution {    public int maxDepth(Node root) {        return helper(root);    }    private int helper(Node root) {        if (root == null) return 0;        int maxDepth = 1;        for (Node node: root.children) {            maxDepth = Math.max(maxDepth, 1+helper(node));        }        return maxDepth;    }}