剑指offer--45.二叉树的深度

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};*/
class Solution {
public:
    int TreeDepth(TreeNode* pRoot)
    {
        if(pRoot == NULL) return 0;
        return max(1+TreeDepth(pRoot->left), 1+TreeDepth(pRoot->right));
    }
};