题解 | #牛群分层排列#
牛群分层排列
https://www.nowcoder.com/practice/7e98027a60424c9ba88d9c4c0506ede4
/** * struct TreeNode { * int val; * struct TreeNode *left; * struct TreeNode *right; * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {} * }; */ #include <vector> class Solution { public: /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param root TreeNode类 * @return string字符串vector */ vector<string> levelOrder(TreeNode* root) { // write code here if(!root) return {}; queue<TreeNode*> cows; vector<string> res; cows.push(root); while (!cows.empty()) { int size=cows.size(); string cs=""; for(int i=0;i<size;i++){ TreeNode *p=cows.front(); cows.pop(); if(!p) continue; cs += to_string(p->val); cows.push(p->left); cows.push(p->right); } if(cs!="") res.push_back(cs); } return res; } };