//--------------------------------------------------- // Purpose: Program to check for prime // numbers using a factoring approach // Author: John Gauch //--------------------------------------------------- #include #include using namespace std; int main() { // Local variable declarations int Number = 0; bool Prime = true; // Read input number cout << "Enter a number between [1..100]: "; cin >> Number; // Check input is valid if ((Number < 1) || (Number > 100)) cout << "Error: Number is out of range\n"; else { // Check if Number is prime if (Number == 1) Prime = false; if ((Number > 2) && (Number % 2 == 0)) Prime = false; if ((Number > 3) && (Number % 3 == 0)) Prime = false; if ((Number > 5) && (Number % 5 == 0)) Prime = false; if ((Number > 7) && (Number % 7 == 0)) Prime = false; // Print output if (Prime) cout << "Number " << Number << " IS prime\n"; else cout << "Number " << Number << " is NOT prime\n"; } return 0; }