怎么做啊，大神们，来看看吧！

#include<iostream>
using namespace std;
class data{
    public:
        int x[4];
        int y[4];
        void encrypt(){
            save();
            for(int i=0;i<4;i++)
            x[i]=(x[i]+7)%10;
            int x=this->x[0];this->x[0]=this->x[2];this->x[2]=x;
            x=this->x[1];this->x[1]=this->x[3];this->x[3]=x;
        }
        void save(){
            for(int i=0;i<4;i++)
            this->y[i]=this->x[i];
        }
        void reversedata(){
            for(int i=0;i<4;i++)
            this->x[i]=this->y[i];
        }
        void display(){
            for(int i=0;i<4;i++)
            cout<<this->x[i];
            cout<<endl;
        }
};
int main(){
    data a;
    for(int i=0;i<4;i++){
        cout<<"请输入第"<<i+1<<"个数据：";
        cin>>a.x[i];
    }
    a.encrypt();
    a.display();
    a.reversedata();
    a.display();   
}