/**
* 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 height = 0;
int dfs(TreeNode* root){
if(root == NULL) return 0;
int height1 = 1 + dfs(root->left);
int height2 = 1 + dfs(root->right);
return max(height1, height2);
}
int treeDepth(TreeNode* root) {
return dfs(root);
}
};