11.17双向循环链表应用

#include<bits/stdc++.h>
using namespace std;
typedef struct f{
    int data;
    f* prior;
    f* next;
}node,*Node;
void build(Node p){
    int n;
    cin>>n;
    while(n--){
        int x;
        cin>>x;
        Node now=new node();
        now->data=x;
        now->prior=p;
        now->next=NULL;
        p->next=now;
        p=p->next;
    }
}

void show(Node p){
    p=p->next;
    while(p!=NULL){
        cout<<p->data;
        p=p->next;
    }
}
 void change(Node p){
    Node o=p;
    p=p->next;
    p=p->next;
    int x;
    cin>>x;
    while(p!=NULL&&p->data!=x){
        p=p->next;
    }
    if(p==NULL){
        cout<<"未找到"<<x;
    }
    else{//调换
        Node pp=p->prior,ep=pp->prior;
        Node a=pp->prior,b=pp,c=p,d=p->next;
        ep->next=p;
        pp->prior=c;
        pp->next=d;
        p->prior=a;
        p->next=b;
        show(o);
    }
}
 
int main(){
    Node p=new node();
    p->next=NULL;
     build(p);
    
     change(p);
    return 0;
}