/*
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) {
queue<TreeNode *> Q;
vector<int> result;
if(root==NULL)return result;
Q.push(root);
while(!Q.empty())
{
TreeNode* p = Q.front();
Q.pop();
result.push_back(p->val);
if(p->left!=NULL)
Q.push(p->left);
if(p->right!=NULL)
Q.push(p->right);
}
return result;
}
};