NC14 按之字形顺序打印二叉树（C++）- 中等、栈、树、队列

题目链接：https://www.nowcoder.com/practice/91b69814117f4e8097390d107d2efbe0?tpId=196&rp=1&ru=%2Fexam%2Foj&qru=%2Fexam%2Foj&sourceUrl=%2Fexam%2Foj%3Fpage%3D2%26tab%3D%25E7%25AE%2597%25E6%25B3%2595%25E7%25AF%2587%26topicId%3D196&difficulty=&judgeStatus=&tags=&title=14&gioEnter=menu
题目如下：

class Solution {
public:
    vector > Print(TreeNode* pRoot) {
        vector> res;
        if(pRoot==nullptr) return res;
        bool flag=true;//之字形标记位
        
        queue que;
        que.push(pRoot);
        while(que.size()!=0){
            int size=que.size();
            vector path;
            
            while(size--){                
                auto temp=que.front();
                path.push_back(temp->val);
                que.pop();//队列用完一个元素，要pop()下
                
                if(temp->left) que.push(temp->left);
                if(temp->right) que.push(temp->right);
                
            }
            
            //之字形反转
            if(flag==false){
                reverse(path.begin(),path.end());
                flag=true;
            }else flag=false;
            
            res.push_back(path);
            
        }
        
        return res;
    }
    
};