冲刺Offer - 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;
        
        int ld = TreeDepth(pRoot->left);
        int rd = TreeDepth(pRoot->right);
        return (ld > rd)?(ld + 1):(rd + 1);
    }
};