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9/PrintFromTopToBottom.h

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+#include<iostream>
+using namespace std;
+#include<vector>
+#include<queue>
+
+struct TreeNode {
+	int val;
+	struct TreeNode *left;
+	struct TreeNode *right;
+	TreeNode(int x) :
+		val(x), left(NULL), right(NULL) {
+	}
+
+};
+
+
+
+
+vector<int> PrintFromTopToBottom(TreeNode *root) 
+{
+	typedef TreeNode Node;
+	vector<int> vec;
+	if (root == NULL) return vec;
+
+	queue<Node*> q;
+	q.push(root);
+	while (!q.empty())
+	{
+		Node* front = q.front();
+		q.pop();
+		vec.push_back(front->val);
+		if (front->left != NULL) q.push(front->left);
+		if (front->right != NULL) q.push(front->right);
+	}
+	return vec;
+}
+
+
+
+
+
+
+