Answer:
#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;
int menu();
int doubleIt(int);
int getPower(int,int);
int reverse(int);
int power(int);
int sum(int);
int twoDigit(int);
int threeDigit(int);
bool prime(int);
int main()
{int n;
srand(time(0));
n=rand()%90+10;
do
{
cout<<"The number is: "<<n<<endl<<endl;
switch(menu())
{case 1: n=doubleIt(n);
break;
case 2: n=reverse(n);
break;
case 3: n=power(n);
break;
case 4: n=sum(n);
break;
case 5: n=twoDigit(n);
break;
case 6: n=threeDigit(n);
break;
case 7: return 0;
}
if(prime(n))
cout<<n<<" is prime\n";
else
cout<<n<<" is not prime\n\n";
if(n<10)
n+=10;
}while(true);
}
int doubleIt(int n)
{return n*2;
}
int power(int n)
{int p;
cout<<"Enter 2, 3 or 4th power: ";
cin>>p;
while(p<2||p>4)
{cout<<"invalid entry\n";
cout<<"Enter 2, 3 or 4th power: ";
cin>>p;
}
return getPower(n,p);
}
int reverse(int n)
{int newnum=0;
while(n>0)
{newnum=newnum*10+n%10;
n=n/10;
}
return newnum;
}
int sum(int n)
{int sum=0;
while(n>0)
{sum=sum+n%10;
n=n/10;
}
return sum;
}
int twoDigit(int n)
{int d1,d2;
if(n<100)
{d1=n%10;
d2=n/10;
return getPower(d1,d2);
}
return n;
}
int threeDigit(int n)
{int d1,n2;
if(n>99)
{d1=n%10;
if(d1<=4)
{n2=n/10;
return getPower(n2,d1);
}
}
return n;
}
bool prime(int n)
{int i;
for(i=2;i<n-1;i++)
if(n%i==0)
return false;
return true;
}
int getPower(int x,int y)
{int ans,i;
if(y==0)
return 1;
else
{ans=x;
for(i=2;i<=y;i++)
ans=ans*x;
return ans;
}
}
int menu()
{int choice=8;
while(choice<1||choice>7)
{cout<<"1. double the number\n";
cout<<"2. reverse the digit of the number\n";
cout<<"3. raise the number to the power of 2,3, or 4\n";
cout<<"4. sum thee digits of the number.\n";
cout<<"5. if the number is a two digit number\n then raise the first digit to the power of the second digit\n";
cout<<"6. If the number is a three digit number\n";
cout<<" and the last digit is less than or equal to 4\n then raise the first two digits to the power of the last digit.\n";
cout<<"7. exit\n";
cin>>choice;
}
return choice;
}
