LeetCode [559] Maximum Depth of N-ary Tree

 559. Maximum Depth of N-ary Tree

Easy

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 depth of the n-ary tree is less than or equal to 1000.
• The total number of nodes is between [0, 10^4].

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/* // Definition for a Node. class Node { public int val; public List<Node> children; public Node() {} public Node(int _val) { val = _val; } public Node(int _val, List<Node> _children) { val = _val; children = _children; } }; */ class Solution { int maxD = 0; public int maxDepth(Node root) { if(root==null) return maxD; dfs(root, 1); return maxD; } void dfs(Node node, int depth){ if(node==null) return; else{ maxD = Math.max(maxD, depth); for(Node c : node.children){ dfs(c, depth+1); } } } }