二叉树的深度（剑指offer）

 1 /*
 2 struct TreeNode {
 3     int val;
 4     struct TreeNode *left;
 5     struct TreeNode *right;
 6     TreeNode(int x) :
 7             val(x), left(NULL), right(NULL) {
 8     }
 9 };*/
10 class Solution {
11 public:
12     int TreeDepth(TreeNode* pRoot)
13     {
14       if(pRoot == NULL){
15             return 0;
16         }
17         int left = 0;
18         int right = 0;
19         left = TreeDepth(pRoot->left);
20         right = TreeDepth(pRoot->right);
21         return (left > right ? left : right) + 1;
22     }
23 };