C++代码实现

//用单链表实现LRU策略   2019.3.17
#include <iostream>
#include <string>
using namespace std;
struct weburl
{string website;weburl *next;};
class webList
{weburl *p_head;size_t cacheSize;
public:webList():p_head(new weburl),cacheSize(0){p_head->next = NULL;    //犯错，开始没有写这句，导致后面有的地方非法访问}~webList(){eraseAll();delete p_head;}void eraseAll(){weburl *tempNode = p_head->next, *del_Node = NULL;while(tempNode != NULL){del_Node = tempNode;tempNode = tempNode->next;delete del_Node;cacheSize--;   
//          tempNode = tempNode->next;    //千万注意顺序，之前放这错了！！！}}weburl* get_head(){return p_head;}weburl* find(string &str){weburl *tempNode = p_head;while(tempNode->next != NULL){if(tempNode->next->website == str)return tempNode;    //返回的是找到的节点的上一个节点elsetempNode = tempNode->next;}return NULL;}size_t getCacheSize(){return cacheSize;}void incrCacheSize(){cacheSize++;}void decrCacheSize(){cacheSize--;}void push_front(weburl *p){p->next = p_head->next;p_head->next = p;incrCacheSize();}void move_to_front(weburl *p){p->next = p_head->next;p_head->next = p;}void pop_back(){weburl *p = p_head, *prev = NULL;while(p->next != NULL){prev = p;p = p->next;}prev->next = NULL;delete p;decrCacheSize();}void printCacheList(){cout << "the recently visit website: " << endl;weburl *tempNode = p_head;size_t i = 0;while(tempNode->next != NULL){tempNode = tempNode->next;cout << ++i << " " << tempNode->website << endl;}}
};
int main()
{char conti = 'y';size_t maxCacheSize = 5;string web;webList cacheList;while(conti == 'y' || conti == 'Y'){cout << "-------------------------------------------" << endl;cout << "please enter the weburl you want to visit: " << endl;cin >> web;weburl *tempNode = cacheList.find(web);weburl *head = cacheList.get_head();if (tempNode == NULL)    //没有找到，是新的访问记录{weburl *newWeb = new weburl;newWeb->website = web;newWeb->next = NULL;if (cacheList.getCacheSize() < maxCacheSize) //存储没满，直接加到队首{cacheList.push_front(newWeb);} else    //存储满了，删除队尾，插入新的到队首{cacheList.pop_back();cacheList.push_front(newWeb);}} else    //从已有的数据中找到了记录{if (tempNode == head)    ;   //记录在第一条，则无需操作else {weburl *mvRecord = tempNode->next;tempNode->next = mvRecord->next;    //把该记录从链表中断开cacheList.move_to_front(mvRecord);  //把该记录移到队首}}cacheList.printCacheList();cout << "continue? y/n" << endl;cin >> conti;cin.get();}return 0;
}