LRU代码实现

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> PII;
#define ls l,mid,rt<<1
#define rs mid+1,r,rt<<1|1
const int MAXN = 1e6+10;
const double EPS = 1e-12;

struct DLink{
    DLink *Pre;
    DLink *Next;
    int key;
    DLink(int x) : key(x),Pre(NULL),Next(NULL){}
};
int sz,cap;
map<int,bool>mp;
DLink *tail=new DLink(0),*head=new DLink(0);

void add(int x){
    DLink *now=new DLink(x);
    head->Next->Pre=now;
    now->Pre=head;
    now->Next=head->Next;
    head->Next=now;
    sz++;
    mp[x]=1;
    if(sz>cap){
        mp[tail->Pre->key]=0;
        tail->Pre->Pre->Next=tail;
        tail->Pre=tail->Pre->Pre;
        sz--;
    }
}

void get(int x){
    if(!mp[x]){
        printf("Can‘t find this page.\n");
    }
    DLink *now=head->Next;
    while(now->key!=x){
        now=now->Next;
    }
    now->Pre->Next=now->Next;
    now->Next->Pre=now->Pre;
    head->Next->Pre=now;
    now->Pre=head;
    now->Next=head->Next;
    head->Next=now;
}

int main()
{
    head->Next=tail;
    tail->Pre=head;
    scanf("%d",&cap);
    /*while(1){
        输入操作
        增加页面：add();
        获取页面：get();
        break;
    }*/
}