//--------------------------------------------------- // Purpose: Program to check for prime // numbers using a factoring approach // Author: John Gauch //--------------------------------------------------- #include #include using namespace std; bool is_prime(int Number) { // Check if Number is prime bool Prime = true; if (Number == 1) Prime = false; for (int Factor = 2; Factor <= sqrt(Number); Factor++) if (Number % Factor == 0) Prime = false; return Prime; } int main() { // Local variable declarations int Number = 0; // Read input number cout << "Enter a number between [1..1000]: "; cin >> Number; // Check input is valid if ((Number < 1) || (Number > 1000)) cout << "Error: Number is out of range\n"; else { // Print output if (is_prime(Number)) cout << "Number " << Number << " IS prime\n"; else cout << "Number " << Number << " is NOT prime\n"; } return 0; }