数据结构-双向循环链表-题解（C++代码）

解题思路:

注意事项:

参考代码:

#include<bits/stdc++.h>
using namespace std;
typedef struct Node{
        int date;
        struct Node* before;
        struct Node* next;
}Node;
typedef struct HeadNode{   
        int Size = 0;   
        Node* first;
}HeadNode;
Node* make_List();
int main(){
        HeadNode* head = new HeadNode;   //头节点
        Node* myList = new Node;
        myList->before = myList;
        myList->next = myList;
        head->first = myList;
        int  which;
        while(cin >> which){
                if(which == 0){   //遍历打印
                        myList = (head->first)->next;
                        int i = 0;
                        while( i++ < head->Size){
                                cout << myList->date << " ";
                                myList = myList->next;
                        }
                        cout << endl;
                }else if(which == 1){   //插入
                        int i , n;
                        cin >> n;
                        Node* p = head->first;
                        for( i = 1; i < n; i++){   //找前一个
                                p = p->next;
                        }
                        Node* a = new Node;
                        cin >> a->date;
                        a->next = p->next;
                        (a->next)->before = a;
                        a->before = p;
                        p->next = a;
                        head->Size++;
                }else if(which == 2){   //删除
                        int i , n;
                        cin >> n;
                        Node* p = head->first;
                        for( i = 0; i < n; i++){   //找到删除那个
                                p = p->next;
                        }
                        (p->before)->next = p->next;
                        (p->next)->before = p->before;
                        delete p;
                        head->Size--;
                }
        }
        return 0;
}