mirror of
https://github.com/freebsd/freebsd-src.git
synced 2024-12-04 03:49:02 +00:00
141 lines
3.9 KiB
C
141 lines
3.9 KiB
C
/*
|
|
* Copyright (c) 1988, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Timothy C. Stoehr.
|
|
*
|
|
* 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 sccsid[] = "@(#)random.c 8.1 (Berkeley) 5/31/93";
|
|
#endif /* not lint */
|
|
|
|
/*
|
|
* random.c
|
|
*
|
|
* This source herein may be modified and/or distributed by anybody who
|
|
* so desires, with the following restrictions:
|
|
* 1.) No portion of this notice shall be removed.
|
|
* 2.) Credit shall not be taken for the creation of this source.
|
|
* 3.) This code is not to be traded, sold, or used for personal
|
|
* gain or profit.
|
|
*
|
|
*/
|
|
|
|
static long rntb[32] = {
|
|
3, 0x9a319039, 0x32d9c024, 0x9b663182, 0x5da1f342,
|
|
0xde3b81e0, 0xdf0a6fb5, 0xf103bc02, 0x48f340fb, 0x7449e56b,
|
|
0xbeb1dbb0, 0xab5c5918, 0x946554fd, 0x8c2e680f, 0xeb3d799f,
|
|
0xb11ee0b7, 0x2d436b86, 0xda672e2a, 0x1588ca88, 0xe369735d,
|
|
0x904f35f7, 0xd7158fd6, 0x6fa6f051, 0x616e6b96, 0xac94efdc,
|
|
0x36413f93, 0xc622c298, 0xf5a42ab8, 0x8a88d77b, 0xf5ad9d0e,
|
|
0x8999220b, 0x27fb47b9
|
|
};
|
|
|
|
static long *fptr = &rntb[4];
|
|
static long *rptr = &rntb[1];
|
|
static long *state = &rntb[1];
|
|
static int rand_type = 3;
|
|
static int rand_deg = 31;
|
|
static int rand_sep = 3;
|
|
static long *end_ptr = &rntb[32];
|
|
|
|
srrandom(x)
|
|
int x;
|
|
{
|
|
register int i;
|
|
long rrandom();
|
|
|
|
state[0] = (long) x;
|
|
if (rand_type != 0) {
|
|
for (i = 1; i < rand_deg; i++) {
|
|
state[i] = 1103515245 * state[i - 1] + 12345;
|
|
}
|
|
fptr = &state[rand_sep];
|
|
rptr = &state[0];
|
|
for (i = 0; i < 10 * rand_deg; i++) {
|
|
(void) rrandom();
|
|
}
|
|
}
|
|
}
|
|
|
|
long
|
|
rrandom()
|
|
{
|
|
long i;
|
|
|
|
if (rand_type == 0) {
|
|
i = state[0] = (state[0]*1103515245 + 12345) & 0x7fffffff;
|
|
} else {
|
|
*fptr += *rptr;
|
|
i = (*fptr >> 1) & 0x7fffffff;
|
|
if (++fptr >= end_ptr) {
|
|
fptr = state;
|
|
++rptr;
|
|
} else {
|
|
if (++rptr >= end_ptr) {
|
|
rptr = state;
|
|
}
|
|
}
|
|
}
|
|
return(i);
|
|
}
|
|
|
|
get_rand(x, y)
|
|
register int x, y;
|
|
{
|
|
register int r, t;
|
|
long lr;
|
|
|
|
if (x > y) {
|
|
t = y;
|
|
y = x;
|
|
x = t;
|
|
}
|
|
lr = rrandom();
|
|
lr &= (long) 0x00003fff;
|
|
r = (int) lr;
|
|
r = (r % ((y - x) + 1)) + x;
|
|
return(r);
|
|
}
|
|
|
|
rand_percent(percentage)
|
|
register int percentage;
|
|
{
|
|
return(get_rand(1, 100) <= percentage);
|
|
}
|
|
|
|
coin_toss()
|
|
{
|
|
|
|
return(((rrandom() & 01) ? 1 : 0));
|
|
}
|