maximum-depth-of-binary-tree.cpp

/**
 * 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;

            int left = maxDepth(root->left);
            int right = maxDepth(root->right);
            if(left>right)
                return left +1;
            else
                return right +1;
            
    }
};