/*
* Copyright 1997 Piermont Information Systems Inc.
* All rights reserved.
*
* Written by Philip A. Nelson for Piermont Information Systems Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of Piermont Information Systems Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY PIERMONT INFORMATION SYSTEMS INC. ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL PIERMONT INFORMATION SYSTEMS INC. BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
#include <stdio.h>
/*
* primes - prime table, built to include up to 46345 because
* sqrt(2^31) = 46340.9500118415
*
* building the table instead of storing a precomputed table saves
* about 19K of space on the binary image.
*/
#ifdef TESTING
long primes[4800];
int num_primes = 2;
static void build_primes (long max);
void factor (long val, long *fact_list, int fact_size, int *num_fact);
static void
build_primes(long max)
{
long pc;
int j;
long rem;
/*
* Initialise primes at run-time rather than compile time
* so it's put in bss rather than data.
*/
primes[0] = 2;
primes[1] = 3;
for (pc = primes[num_primes-1]; pc < 46345 && pc*pc <= max; pc+=2) {
j = 0;
rem = 1;
while (j < num_primes && primes[j] * primes[j] <= pc) {
if ((rem = pc % primes[j]) == 0)
break;
j++;
}
if (rem)
primes[num_primes++] = pc;
}
}
/* factor: prepare a list of prime factors of val.
The last number may not be a prime factor if the list is not
long enough. */
void
factor(long val, long *fact_list, int fact_size, int *num_fact)
{
int i;
/* Check to make sure we have enough primes. */
build_primes(val);
i = 0;
*num_fact = 0;
while (*num_fact < fact_size-1 && val > 1 && i < num_primes) {
/* Find the next prime that divides. */
while (i < num_primes && val % primes[i] != 0) i++;
/* Put factors in array. */
while (*num_fact < fact_size-1 && i < num_primes &&
val % primes[i] == 0) {
fact_list[(*num_fact)++] = primes[i];
val /= primes[i];
}
}
if (val > 1)
fact_list[(*num_fact)++] = val;
}
#include <stdio.h>
#include <stdlib.h>
int
main(int argc, char **argv)
{
long facts[30];
long val;
int i, nfact;
int arg;
