/*********************************************************
 * From C PROGRAMMING: A MODERN APPROACH, Second Edition *
 * By K. N. King                                         *
 * Copyright (c) 2008, 1996 W. W. Norton & Company, Inc. *
 * All rights reserved.                                  *
 * This program may be freely distributed for class use, *
 * provided that this copyright notice is retained.      *
 *********************************************************/

/* prime.c (Chapter 9, page 190) */
/* Tests whether a number is prime */

#include <stdbool.h>   /* C99 only */
#include <stdio.h>

bool is_prime(int n)
{
  int divisor;

  if (n <= 1)
    return false;
  for (divisor = 2; divisor * divisor <= n; divisor++)
    if (n % divisor == 0)
      return false;
  return true;
}

int main(void)
{
  int n;

  printf("Enter a number: ");
  scanf("%d", &n);
  if (is_prime(n))
    printf("Prime\n");
  else
    printf("Not prime\n");

  return 0;
}