双向循环链表C++实现（完整版）

#include<iostream>using namespace std;/**节点类*/struct DCNode{  int data;  DCNode * prior;  DCNode * next;};/**链表类*/struct DCList{DCList(){size = 0;}size_t size;//记录节点数的个数DCNode * head;//指向链表的头结点};/**分配一个节点，并给该节点的数据域赋值，默认值为0；*/DCNode * MakeNode(int t=0){DCNode * p = (DCNode *)malloc(sizeof(DCNode));p->data = t;return p;}//初始化一个空的双向循环链表void InitDCList(DCList &list){//分配一个头结点DCNode * p = MakeNode();list.head = p;list.size = 0;p->next = p;p->prior = p;}//释放所指向的节点void FreeNode(DCNode * p){delete p;}//清空一个线性表void clear(DCList &list){DCNode * p = list.head;p = p->next;while(p!= list.head){  DCNode * p1 = p->next;delete p;p = p1;}list.size = 0;}//将s所指向的节点插入到链表的第一个节点之前bool InsFirst(DCList &list,DCNode * s){s->next = list.head->next;list.head->next->prior = s;list.head->next = s;s->prior = list.head;list.size++;return true;}//删除链表中的第一个节点并以q指针返回bool DelFirst(DCList &list,DCNode *  & q){if(list.head->next==list.head)//如果链表为空{q = 0;return false;}q = list.head->next;list.head->next->next->prior = list.head;list.head->next = list.head->next->next;list.size--;return true;}//将s所指向的节点串接在链表的最后一个节点之后bool Append(DCList &list,DCNode * s){s->prior = list.head->prior;s->next = list.head;list.head->prior->next = s;list.head->prior = s;list.size++;return true;}//删除链表中的尾节点,并以指针q返回bool Remove(DCList &list,DCNode * & q){if(list.head->next==list.head)//如果链表为空{q = 0;return false;}q = list.head->prior;list.head->prior->prior->next = list.head;list.head->prior = list.head->prior->prior;list.size--;return true;}//将s所指向的节点插入链表中p所指向的节点之前bool InsBefore(DCList &list,DCNode * p,DCNode * s){DCNode * p1 = list.head->next;while(p1!=list.head){ if(p1==p)//找到该链表中是否存在p所指向的节点 { s->next = p; s->prior = p->prior; p->prior->next = s; p->prior = s; list.size++;     return true; }  p1 = p1->next;}//没找到return false;}//将s所指向的节点插入链表中p所指向的节点之后bool InsAfter(DCList &list,DCNode * p,DCNode * s){DCNode * p1 = list.head->next;while(p1!=list.head){ if(p1==p)//找到该链表中是否存在p所指向的节点 { s->next = p->next; s->prior = p; p->next->prior = s; p->next = s; list.size++;     return true; } p1 = p1->next;}//没找到return false;}//判断链表是否为空bool Empty(DCList &list){if(list.size==0)return  true;elsereturn false;}//返回链表的长度int GetLength(DCList &list){return list.size;}//返回链表中第i个节点的指针DCNode * LocatePos(DCList &list,int i){if(i<=0&&i>(int)list.size ) return 0;//如果不存在第i个节点则返回一个0指针int n = 0;DCNode * p1 = list.head->next;while(p1!=list.head){ n++; if(n==i)//找到 {return p1; } p1 = p1->next;}return 0;}//在链表中查找第一个元素值与t相等的节点指针DCNode * LocateElem(DCList &list,int t){if(list.head->next==list.head)//如果链表为空{return 0;}DCNode * p1 = list.head->next;while(p1!=list.head){if(p1->data==t)//找到 {return p1; } p1 = p1->next;}return 0;}//在链表中查找第一个元素值与t满足compare函数关系的节点指针DCNode * LocateElem(DCList &list,int t,bool (* compare)(int ,int)){if(list.head->next==list.head)//如果链表为空{return 0;}DCNode * p1 = list.head->next;while(p1!=list.head){if((*compare)(p1->data,t))//找到了 {return p1; } p1 = p1->next;}return 0;}//依次对链表中的每一个元素调用visit函数，一旦visit函数调用失败，则整个操作失败bool ListTraverse(DCList &list,bool (*visit)(int &)){DCNode * p1 = list.head->next;while(p1!=list.head){if(!(*visit)(p1->data))//找到了 {return false; } p1 = p1->next;}return true;}//合并两个双向循环链表DCList & MergeList(DCList &list1,DCList &list2){if(Empty(list1)){return list2;}if(Empty(list2)){return list1;}list1.head->prior->next = list2.head->next;list2.head->next->prior = list1.head->prior;list1.head->prior = list2.head->prior;list2.head->prior->next = list1.head;return list1;}//判断是否一个数为偶数bool judge(int a,int b){if(a%b==0) return true;return false;}bool visit(int & t){t = t+1;return true;}int main(){//创建并初始化一个空的双向循环链表DCList myList;InitDCList(myList);//在链表的尾端添加元素//现分配一个节点DCNode * s = MakeNode(1);Append(myList,s);s = MakeNode(3);Append(myList,s);s = MakeNode(5);Append(myList,s);s = MakeNode(7);Append(myList,s);//遍历该链表，并输出该链表的元素个数DCNode * p1 = myList.head->next;cout<<"新建一个双向链表，并初始化元素值为1，3，5，7"<<endl;while(p1!=myList.head){cout<<p1->data<<"  "; p1 = p1->next;}cout<<endl;cout<<"链表的元素个数为:"<<GetLength(myList)<<endl;//在链表的第一个数据节点之前插入两个元素s = MakeNode(9);InsFirst(myList,s);s = MakeNode(0);InsFirst(myList,s); cout<<"在链表的第一个数据节点之前插入两个元素值为0，9的节点:"<<endl; p1 = myList.head->next;while(p1!=myList.head){cout<<p1->data<<"  "; p1 = p1->next;}cout<<endl;//删除链表中的第一个节点和尾节点  cout<<"删除的第一个节点"<<endl; if(DelFirst(myList,s)) { cout<<"被删除的第一个节点数据为："<<s->data<<endl; }  p1 = myList.head->next;while(p1!=myList.head){cout<<p1->data<<"  "; p1 = p1->next;}cout<<endl;//释放被删除的节点空间 FreeNode(s); cout<<"删除的尾节点"<<endl;if( Remove(myList,s) ){ cout<<"被删除的尾节点数据为："<<s->data<<endl;} p1 = myList.head->next;while(p1!=myList.head){cout<<p1->data<<"  "; p1 = p1->next;}cout<<endl;//释放被删除的节点空间FreeNode(s);//在第二个节点之前插入元素 p1 = LocatePos(myList,2); cout<<"第二个节点数据为："<<p1->data<<endl; s = MakeNode(11); InsBefore(myList,p1,s); cout<<"在第二个节点之前插入一个元素值为11的新节点:"<<endl; p1 = myList.head->next; while(p1!=myList.head) {cout<<p1->data<<"  "; p1 = p1->next; } cout<<endl;//在第二个节点之后插入元素 s = MakeNode(16); p1 = LocatePos(myList,2); InsAfter(myList,p1,s); cout<<"再在第二个节点之后插入一个元素值为16的新节点:"<<endl; p1 = myList.head->next; while(p1!=myList.head) {cout<<p1->data<<"  "; p1 = p1->next; } cout<<endl;//查找第一个元素值为4的倍数的节点 p1 = LocateElem(myList,4,judge); cout<<"找到第一个元素值为4的倍数的节点数据为："<<p1->data<<endl;//将链表中所有的元素值都增加1 ListTraverse(myList,visit); cout<<"将链表中所有的元素值都增加1:"<<endl; p1 = myList.head->next; while(p1!=myList.head) {cout<<p1->data<<"  "; p1 = p1->next; } cout<<endl;//新建一个元素值为1，3，9的链表 DCList myList2;InitDCList(myList2);//在链表的尾端添加元素//现分配一个节点 s = MakeNode(1);Append(myList2,s);s = MakeNode(3);Append(myList2,s);s = MakeNode(9);Append(myList2,s);//遍历该链表，并输出该链表的元素个数 cout<<"新建一个元素值为1，3，9的链表:"<<endl;    p1 = myList2.head->next;while(p1!=myList2.head){cout<<p1->data<<"  "; p1 = p1->next;}cout<<endl;//合并两个链表 myList = MergeList(myList,myList2); cout<<"合并两个链表:"<<endl; p1 = myList.head->next; while(p1!=myList.head) {cout<<p1->data<<"  ";    p1 = p1->next; } cout<<endl; cout<<"最后清空myList链表！"<<endl; clear(myList);}