LeetCode 104. Maximum Depth of Binary Tree

/**
* 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==NULL)
return 0;
else
{
int l=maxDepth(root->left);
int r=maxDepth(root->right);
return r>l?r+1:l+1;
}

}
};