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using namespace std;
//A simple and efficient implementation of a function to test if a number is prime, based on the fact that
//Every Prime number, except 2 and 3 are of the form 6*k+1 or 6*k-1 for integer values of k.
bool IsPrime(int number)
if (((!(number & 1)) && number != 2) || (number < 2) || (number % 3 == 0 && number != 3))
for (int k = 1; 36 * k * k - 12 * k < number; ++k)
if ((number % (6 * k + 1) == 0) || (number % (6 * k - 1) == 0))
cout << "Enter the value of n to check if Prime\n";
cin >> n;
cout << n << " is Prime" << endl;
cout << n << " is not Prime" << endl;