LeetCode_429_N叉樹的層序周遊

題目描述：

/*
// 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) {
        vector<vector<int>> res;
        if(!root)
            return res;
        queue<Node*> que;
        que.push(root);
        while(!que.empty()){
            int size=que.size();//統計同一層的節點個數
            vector<int> leveltemp;
            while(size--){
                Node* now=que.front();
                que.pop();
                leveltemp.push_back(now->val);
                for(Node* child:now->children)
                    que.push(child);
            }
            res.push_back(leveltemp);
        }
        return res;
    }
};