课堂作业——图书最优购买

#include<iostream.h>
int main()
{
    int i,j,k;
    double sum=0;
    cout<<"请输入购买图书本数"<<endl;
    cin>>i;
    j=i/5;
    k=i%5;
    if(k==0){
    sum=j*30;
    }
    else if(k==1){
        sum=j*30+8;
    }
    else if(k==2){
        sum=j*30+16*0.95;
    }
    else if(k==3){
        sum=(j-1)*30+64*0.8;
    }
    else if(k==4){
        sum=j*30+32*0.8;
    }
    cout<<"最优惠价格为:"<<sum<<endl;
    return 0;
}