HELP writing code to check # if it is prime or not

[chrispy232]

This code allowed me to check if a number is a prime or not by outputting a 0 or a 1. My question, is how to get this code to not run when someone inputs 1 number but multiple. For example, after it check 4, it outputs 0 and the program is done. I want it to keep going.

#include <iostream>
using std::cin;
using std::cout;
using std;;endl;
#include <cmath>

int main(){
while (true){
int n;
cin>>n;
for (int k=2; k<=n-1; k++){
if (n%k==0){
cout<<"0"<<endl;
return (true);}
else if (n%k!=0){
cout<<"1"<<endl;
return (true);
break;}}
}
return 0;}

[icy1]

firstly, please do formatting with the [ code ] [ /code ] tags (no spaces near brackets).

Come up with an exit case -- for example, declare n outside the while loop and change while condition to while(n != -1) , so that you can enter -1 to exit.

In your "if" statements, you have two returns. Get rid of those -- the returns, since they're in the main() method, will exit the whole program. You only need the last return 0;

Consider also looking up an algorithm for checking prime (I think Euler has an easy one). You currently just check divisibility by two, and you're checking too many numbers.

gl