//104
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.
class Solution {
public:
int maxDepth(TreeNode* root) {
if(root==NULL){
return 0;
}
int leftTree=maxDepth(root->left);
int rightTree=maxDepth(root->right);
return max(leftTree,rightTree)+1;
}
};
