1. 题目

返回其层序遍历:[[1],[3,2,4],[5,6]
]

2. 解题

• queue队列解题

/*
// Definition for a Node.
class Node {
public:int val;vector<Node*> children;Node() {}Node(int _val, vector<Node*> _children) {val = _val;children = _children;}
};
*/
class Solution {
public:vector<vector<int>> levelOrder(Node* root) {if(root == NULL)return {};vector<vector<int>> ans;vector<int> lv;int Num, i;queue<Node*> q;q.push(root);while(!q.empty()){lv.clear();Num = q.size();while(Num--){lv.push_back(q.front()->val);for(i = 0; i < q.front()->children.size(); ++i)q.push(q.front()->children[i]);q.pop();}ans.push_back(lv);}return ans;}
};