Description

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.

Code

Maximum Depth of Binary Tree 的 generalized 版本。

/*
// Definition for a Node.
class Node {
public:
    int val;
    vector<Node*> children;
 
    Node() {}
 
    Node(int _val) {
        val = _val;
    }
 
    Node(int _val, vector<Node*> _children) {
        val = _val;
        children = _children;
    }
};
*/
 
class Solution {
public:
    int maxDepth(Node* root) {
        if(!root) return 0;
        int tempMax = 0;
        for(auto child: root->children) {
            tempMax = max(tempMax, maxDepth(child));
        }
        return tempMax + 1;
    }
};

Source