从上往下打印二叉树
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。 ***
思路
BFS广搜模板题。。没啥好说的吧
C++实现
/*
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> vc;
queue<TreeNode*> q;
q.push(root);
while(!q.empty()){
TreeNode* temp=q.front();
q.pop();
if(!temp)
continue;
vc.push_back(temp -> val);
q.push(temp -> left);
q.push(temp -> right);
}
return vc;
}
};