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mirror of https://git.FreeBSD.org/src.git synced 2024-12-23 11:18:54 +00:00
freebsd/games/factor/factor.c
Jordan K. Hubbard 554eb505f8 Bring in the 4.4 Lite games directory, modulo man page changes and segregation
of the x11 based games.  I'm not going to tag the originals with bsd_44_lite
and do this in two stages since it's just not worth it for this collection,
and I've got directory renames to deal with that way.  Bleah.
Submitted by:	jkh
1994-09-04 04:03:31 +00:00

202 lines
5.4 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Landon Curt Noll.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)factor.c 8.3 (Berkeley) 3/30/94";
#endif /* not lint */
/*
* factor - factor a number into primes
*
* By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo
*
* chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
*
* usage:
* factor [number] ...
*
* The form of the output is:
*
* number: factor1 factor1 factor2 factor3 factor3 factor3 ...
*
* where factor1 < factor2 < factor3 < ...
*
* If no args are given, the list of numbers are read from stdin.
*/
#include <err.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include "primes.h"
/*
* prime[i] is the (i-1)th prime.
*
* We are able to sieve 2^32-1 because this byte table yields all primes
* up to 65537 and 65537^2 > 2^32-1.
*/
extern ubig prime[];
extern ubig *pr_limit; /* largest prime in the prime array */
void pr_fact __P((ubig)); /* print factors of a value */
void usage __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
ubig val;
int ch;
char *p, buf[100]; /* > max number of digits. */
while ((ch = getopt(argc, argv, "")) != EOF)
switch (ch) {
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
/* No args supplied, read numbers from stdin. */
if (argc == 0)
for (;;) {
if (fgets(buf, sizeof(buf), stdin) == NULL) {
if (ferror(stdin))
err(1, "stdin");
exit (0);
}
for (p = buf; isblank(*p); ++p);
if (*p == '\n' || *p == '\0')
continue;
if (*p == '-')
errx(1, "negative numbers aren't permitted.");
errno = 0;
val = strtoul(buf, &p, 10);
if (errno)
err(1, "%s", buf);
if (*p != '\n')
errx(1, "%s: illegal numeric format.", buf);
pr_fact(val);
}
/* Factor the arguments. */
else
for (; *argv != NULL; ++argv) {
if (argv[0][0] == '-')
errx(1, "negative numbers aren't permitted.");
errno = 0;
val = strtoul(argv[0], &p, 10);
if (errno)
err(1, "%s", argv[0]);
if (*p != '\0')
errx(1, "%s: illegal numeric format.", argv[0]);
pr_fact(val);
}
exit(0);
}
/*
* pr_fact - print the factors of a number
*
* If the number is 0 or 1, then print the number and return.
* If the number is < 0, print -1, negate the number and continue
* processing.
*
* Print the factors of the number, from the lowest to the highest.
* A factor will be printed numtiple times if it divides the value
* multiple times.
*
* Factors are printed with leading tabs.
*/
void
pr_fact(val)
ubig val; /* Factor this value. */
{
ubig *fact; /* The factor found. */
/* Firewall - catch 0 and 1. */
if (val == 0) /* Historical practice; 0 just exits. */
exit(0);
if (val == 1) {
(void)printf("1: 1\n");
return;
}
/* Factor value. */
(void)printf("%lu:", val);
for (fact = &prime[0]; val > 1; ++fact) {
/* Look for the smallest factor. */
do {
if (val % (long)*fact == 0)
break;
} while (++fact <= pr_limit);
/* Watch for primes larger than the table. */
if (fact > pr_limit) {
(void)printf(" %lu", val);
break;
}
/* Divide factor out until none are left. */
do {
(void)printf(" %lu", *fact);
val /= (long)*fact;
} while ((val % (long)*fact) == 0);
/* Let the user know we're doing something. */
(void)fflush(stdout);
}
(void)putchar('\n');
}
void
usage()
{
(void)fprintf(stderr, "usage: factor [value ...]\n");
exit (0);
}