This is the basic calculator problem of challenges:
#include
using namespace std;
int main() {
char ch;
int n1,n2;
cin>>ch;
while(ch!='x'||ch!='X')
{
switch(ch)
{
case '+':
cin>>n1;
cin>>n2;
if(n1>=0&&n1<=100000000&&n2>=0&&n2<=100000000)
cout<<(n1+n2)<<endl;
break;
case '-':
cin>>n1;
cin>>n2;
if(n1>=0&&n1<=100000000&&n2>=0&&n2<=100000000)
cout<<(n1-n2)<<endl;
break;
case '*':
cin>>n1;
cin>>n2;
if(n1>=0&&n1<=100000000&&n2>=0&&n2<=100000000)
cout<<(n1*n2)<<endl;
break;
case '/':
cin>>n1;
cin>>n2;
if(n1>=0&&n1<=100000000&&n2>0&&n2<=100000000)
cout<<(n1/n2)<<endl;
break;
case '%':
cin>>n1;
cin>>n2;
if(n1>=0&&n1<=100000000&&n2>0&&n2<=100000000)
cout<<(n1%n2)<<endl;
break;
case 'x':
case 'X':
break;
default:
cout<<"Invalid operation. Try again."<<endl;
exit(0);
break;
}
cin>>ch;
}
return 0;
}