给定一个二叉树，找出其最大深度。
二叉树的深度为根节点到最远叶子节点的距离。
/**
* Definition of TreeNode:
* class TreeNode {
* public:
* int val;
* TreeNode *left, *right;
* TreeNode(int val) {
* this->val = val;
* this->left = this->right = NULL;
* }
* }
*/
class Solution {
public:
/**
* @param root: The root of binary tree.
* @return: An integer
*/
int maxDepth(TreeNode *root) {
// write your code here
if(root!=NULL){
int left=maxDepth(root->left);
int right=maxDepth(root->right);
return left>right?left+1:right+1;
}
else{
return 0;
}
}
};
