Check if a number is Quartan Prime or not | Utility function to check if a number is prime or not ; Corner cases ; This is checked so that we can skip middle five numbers in below loop ; Driver Code ; Check if number is prime and of the form 16 * n + 1
def isPrime ( n ) : NEW_LINE INDENT if ( n <= 1 ) : NEW_LINE INDENT return False NEW_LINE DEDENT if ( n <= 3 ) : NEW_LINE INDENT return True NEW_LINE DEDENT if ( n % 2 == 0 or n % 3 == 0 ) : NEW_LINE INDENT return False NEW_LINE DEDENT i = 5 NEW_LINE while ( i * i <= n ) : NEW_LINE INDENT if ( n % i == 0 or n % ( i + 2 ) == 0 ) : NEW_LINE INDENT return False NEW_LINE DEDENT i = i + 6 NEW_LINE DEDENT return True NEW_LINE DEDENT n = 17 NEW_LINE if ( isPrime ( n ) and ( n % 16 == 1 ) ) : NEW_LINE INDENT print ( " YES " ) NEW_LINE DEDENT else : NEW_LINE INDENT print ( " NO " ) NEW_LINE DEDENT