https://leetcode.com/problems/maximum-depth-of-binary-tree/
Given a binary 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.
Note: A leaf is a node with no children.
Example:
Given binary tree [3,9,20,null,null,15,7],
3
/
9 20
/
15 7
return its depth = 3.
代码：
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
int maxDepth(TreeNode* root) {
if(!root) return NULL;
int h1 = 1, h2 = 1;
if(root -> left != NULL)
h1 = maxDepth(root -> left) + 1;
if(root -> right != NULL)
h2 = maxDepth(root -> right) + 1;
return max(h1, h2);
}
};
今天是学习各种树的开始