leetcode-559-easy

Maximum Depth of N-ary Tree

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.

Nary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).

Example 1:

Input: root = [1,null,3,2,4,null,5,6]
Output: 3
Example 2:

Input: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]
Output: 5
Constraints:

The total number of nodes is in the range [0, 104].
The depth of the n-ary tree is less than or equal to 1000.

思路一：递归遍历每个子节点，取最大深度的子节点

    public int maxDepth(Node root) {
        if (root == null) {
            return 0;
        }

        int max = 0;
        for (Node child : root.children) {
            max = Math.max(max, maxDepth(child));
        }

        return max + 1;
    }