题目描述
从上到下按层打印二叉树,同一层结点从左至右输出。每一层输出一行。
代码:层次遍历,简单
class Solution {
public:
vector<vector<int> > Print(TreeNode* root) {
vector<vector<int> >ans;
if(root==NULL)return ans;
queue<TreeNode*>q;
q.push(root);
while(!q.empty()){
queue<TreeNode*>qt;
vector<int>res;
while(!q.empty()){
TreeNode*t=q.front();q.pop();
res.push_back(t->val);
if(t->left)qt.push(t->left);
if(t->right)qt.push(t->right);
}
ans.push_back(res);
q=qt;
}
return ans;
}
};