/*
 * isprime.c - test an integer >= 2 for primality.
 *
 * This function just tries to divide the argument, p, by all integers from
 * 2 to sqrt(p) inclusive.  There are better algorithms.
 *
 * Alan J Rosenthal, September 2000.
 */

#include <math.h>
#include "isprime.h"

/*
 * return true or false to indicate whether p is prime.
 * p must be >= 2.
 */
int isprime(int p)
{
    int d;
    int howfar = (int)sqrt(p);

    for (d = 2; d <= howfar; d = d + 1)
	if (p % d == 0)
	    return 0;

    return 1;
}