剑指offer---二叉树的深度

输入一棵二叉树，求该树的深度。从根结点到叶结点依次经过的结点（含根、叶结点）形成树的一条路径，最长路径的长度为树的深度。

---

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