买书问题

 1 #include<iostream.h>
 2 int main(){
 3     int num;
 4     int m,n;
 5     float sum;
 6     cout<<"请输入要购买的书的本书:";
 7     cin>>num;
 8     m=num/5;
 9     n=num%5;
10     if(num!=3)
11     {
12         switch(n)
13         {
14         case 0:
15             sum=num*8*0.75;
16             break;
17         case 1:
18             sum=m*5*8*0.75+8;
19             break;
20         case 2:
21             sum=m*5*8*0.75+2*8*0.95;
22             break;
23         case 3:
24             sum=(m-1)*5*8+4*8*0.8+4*8*0.8;
25             break;
26         case 4:
27             sum=m*5*0.75+4*8*0.8;
28             break;
29         }
30     }
31     else
32         sum=3*8*0.9;
33     cout<<"读者购买一批书的最低价格为:"<<sum<<"元"<<endl;
34     return 0;
35 }