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。
/* struct TreeNode { int val; struct TreeNode *left; struct TreeNode *right; TreeNode(int x) : val(x), left(NULL), right(NULL) { } }; */ class Solution { vector<vector<int> > res; public: vector<vector<int> > Print(TreeNode* pRoot) { if(!pRoot) return res; queue<TreeNode*> que; que.push(pRoot); while(!que.empty()){ vector<int> v; int s=que.size(); TreeNode* node=nullptr; for(int i=0;i<s;++i){ node=que.front(); v.push_back(node->val); que.pop(); if(node->left) que.push(node->left); if(node->right) que.push(node->right); } res.push_back(v); } return res; } };