c++实现双向循环链表

#pragma once#include #include using namespace std;template struct ListNode{ListNode(T x):data(x),front(this),back(this){}T data;ListNode *front;ListNode *back;};template class List_double{public:List_double();List_double(const List_double& other);List_double& operator = (const List_double& other);~List_double();public:void InsertNode(T x, ListNode *temp = NULL);T DeleteNode(ListNode *del = NULL);ListNode* Find(T x);void PrintFront();void PrintBack();public:ListNode *head;};template List_double::List_double(){head = NULL;}template List_double::List_double(const List_double& other){head = NULL;ListNode *cur = other.head;while (cur){InsertNode(cur->data);cur = cur->front;if (cur == other.head)break;}}template void List_double::InsertNode(T x, ListNode *ins = NULL)//在节点ins之后插入，默认插入表后{ListNode *temp = new ListNode(x);if (head == NULL){head = temp;return;}if (ins == NULL){temp->front = head->front;temp->back = head;temp->back->front = temp;temp->front->back = temp;}else{temp->front = ins;temp->back = ins->back;temp->back->front = temp;temp->front->back = temp;}}template List_double& List_double::operator = (const List_double& other){head = NULL;ListNode *cur = other.head;while (cur){InsertNode(cur->data);cur = cur->front;if (cur == other.head)break;}}template List_double::~List_double(){while (head->front != head){DeleteNode();}delete head;}template T List_double::DeleteNode(ListNode *del = NULL)//默认删除表后数据，删除del所指位置{assert(head != NULL);T ret;if (head->front == head){ret = head->data;delete head;head = NULL;return ret;}if (del == NULL){head->front = head->front->front;ret = head->front->back->data;delete head->front->back;head->front->back = head;return ret;}else{del->front->back = del->back;del->back->front = del->front;ret = del->data;delete del;return ret;}}template ListNode* List_double::Find(T x){ListNode *p = head->front;while (p){if (p == head){if (p->data == x)return p;elsereturn NULL;}if (p->data == x){return p;}else{p = p->front;}}}template void List_double::PrintFront(){ListNode *p = head;while (p){if (p == head->front){cout << p->data << ' ';return;}else{cout << p->data << ' ';p = p->back;}}}template void List_double::PrintBack(){ListNode *p = head->front;while (p){if (p == head){cout << p->data << ' ';return;}else{cout << p->data << ' ';p = p->front;}}}#include #include #include "List.h"using namespace std;int main(){int n;cout << "操作：增加（1），删除（2），从前往后输出（3），从后往前输出（4），查找（5）" << endl;List_double list;while (cin >> n){if (n == 0)break;switch (n){case 1:int tt;cout << "请输入增加的数据int：" << endl;cin >> tt;list.InsertNode(tt);break;case 2:cout << "删除的数据为" << list.DeleteNode() << endl;;break;case 3:list.PrintFront();break;case 4:list.PrintBack();break;case 5:int ttt;cout << "请输入查找的数据int：" << endl;cin >> ttt;if (list.Find(ttt) == NULL)cout << "没有此数据" << endl;elsecout << "存在此数据" << endl;break;}cout << "操作：增加（1），删除（2），从前往后输出（3），从后往前输出（4），查找（5）" << endl;}getchar();getchar();return 0;}