通过测试用例4/10; 骚操作。

/*
struct TreeNode {
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
			val(x), left(NULL), right(NULL) {
	}
};*/
class Solution {
public:
    vector<int> PrintFromTopToBottom(TreeNode* root) {
        vector<int> v;
        fun(root,v);
        return v;
    }
     void fun(TreeNode* root,vector<int> &v){
        if(root!=NULL){
            v.push_back(root->val);
            fun(root->left,v);
            fun(root->right,v);
        }
         
    }
};