层次打印二叉树

 

题目描述

从上往下打印出二叉树的每个节点，同层节点从左至右打印。

---

/*
struct TreeNode {
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
			val(x), left(NULL), right(NULL) {
	}
};*/
class Solution {
public:
    queue<TreeNode * >qu1;
       
    vector<int> PrintFromTopToBottom(TreeNode* root) {
        vector<int> ss1;
        if(root==NULL)
            return ss1;
        qu1.push(root);
        while (!qu1.empty()){
            TreeNode* ab=qu1.front();
            qu1.pop();
            ss1.push_back(ab->val);
            findTree(ab);
        }
            
        return ss1; 
    }
    
    void findTree(TreeNode* a){
        if(a!=NULL){
            if(a->left!=NULL){
                qu1.push(a->left);
            }
            if(a->right!=NULL){
                qu1.push(a->right);
            }
        }
    }
    
    
};