Ensure that the random hop delta does make the cave connected. Based

on bug report and patch from <afghan@afghanhound.org.uk>.
This commit is contained in:
jsm 2001-08-31 07:16:22 +00:00
parent 20af46d385
commit a9d4ab8d8a
1 changed files with 23 additions and 4 deletions

View File

@ -1,4 +1,4 @@
/* $NetBSD: wump.c,v 1.13 2000/05/08 07:56:06 mycroft Exp $ */
/* $NetBSD: wump.c,v 1.14 2001/08/31 07:16:22 jsm Exp $ */
/*
* Copyright (c) 1989, 1993
@ -47,7 +47,7 @@ __COPYRIGHT("@(#) Copyright (c) 1989, 1993\n\
#if 0
static char sccsid[] = "@(#)wump.c 8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: wump.c,v 1.13 2000/05/08 07:56:06 mycroft Exp $");
__RCSID("$NetBSD: wump.c,v 1.14 2001/08/31 07:16:22 jsm Exp $");
#endif
#endif /* not lint */
@ -120,6 +120,7 @@ int bats_nearby __P((void));
void cave_init __P((void));
void clear_things_in_cave __P((void));
void display_room_stats __P((void));
int gcd __P((int, int));
int getans __P((const char *));
void initialize_things_in_cave __P((void));
void instructions __P((void));
@ -520,6 +521,18 @@ The arrow is weakly shot and can go no further!\n");
return(0);
}
int
gcd(a, b)
int a, b;
{
int r;
r = a % b;
if (r == 0)
return (b);
return (gcd(b, r));
}
void
cave_init()
{
@ -542,8 +555,14 @@ cave_init()
for (j = 0; j < link_num ; ++j)
cave[i].tunnel[j] = -1;
/* choose a random 'hop' delta for our guaranteed link */
while (!(delta = random() % room_num));
/*
* Choose a random 'hop' delta for our guaranteed link.
* To keep the cave connected, we need the greatest common divisor
* of (delta + 1) and room_num to be 1.
*/
do {
delta = (random() % (room_num - 1)) + 1;
} while (gcd(room_num, delta + 1) != 1);
for (i = 1; i <= room_num; ++i) {
link = ((i + delta) % room_num) + 1; /* connection */