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/* SCCS Id: @(#)rnd.c 3.4 1996/02/07 */
/* NetHack may be freely redistributed. See license for details. */
#include "hack.h"
/* "Rand()"s definition is determined by [OS]conf.h */
#if defined(LINT) && defined(UNIX) /* rand() is long... */
extern int NDECL(rand);
#define RND(x) (rand() % x)
#else /* LINT */
# if defined(UNIX) || defined(RANDOM)
#define RND(x) (int)(Rand() % (long)(x))
# else
/* Good luck: the bottom order bits are cyclic. */
#define RND(x) (int)((Rand()>>3) % (x))
# endif
#endif /* LINT */
#ifdef OVL0
int
rn2(x) /* 0 <= rn2(x) < x */
register int x;
{
#ifdef DEBUG
if (x <= 0) {
impossible("rn2(%d) attempted", x);
return(0);
}
x = RND(x);
return(x);
#else
return(RND(x));
#endif
}
#endif /* OVL0 */
#ifdef OVLB
int
rnl(x) /* 0 <= rnl(x) < x; sometimes subtracting Luck */
register int x; /* good luck approaches 0, bad luck approaches (x-1) */
{
register int i;
#ifdef DEBUG
if (x <= 0) {
impossible("rnl(%d) attempted", x);
return(0);
}
#endif
i = RND(x);
if (Luck && rn2(50 - Luck)) {
i -= (x <= 15 && Luck >= -5 ? Luck/3 : Luck);
if (i < 0) i = 0;
else if (i >= x) i = x-1;
}
return i;
}
#endif /* OVLB */
#ifdef OVL0
int
rnd(x) /* 1 <= rnd(x) <= x */
register int x;
{
#ifdef DEBUG
if (x <= 0) {
impossible("rnd(%d) attempted", x);
return(1);
}
x = RND(x)+1;
return(x);
#else
return(RND(x)+1);
#endif
}
#endif /* OVL0 */
#ifdef OVL1
int
d(n,x) /* n <= d(n,x) <= (n*x) */
register int n, x;
{
register int tmp = n;
#ifdef DEBUG
if (x < 0 || n < 0 || (x == 0 && n != 0)) {
impossible("d(%d,%d) attempted", n, x);
return(1);
}
#endif
while(n--) tmp += RND(x);
return(tmp); /* Alea iacta est. -- J.C. */
}
#endif /* OVL1 */
#ifdef OVLB
int
rne(x)
register int x;
{
register int tmp, utmp;
utmp = (u.ulevel < 15) ? 5 : u.ulevel/3;
tmp = 1;
while (tmp < utmp && !rn2(x))
tmp++;
return tmp;
/* was:
* tmp = 1;
* while(!rn2(x)) tmp++;
* return(min(tmp,(u.ulevel < 15) ? 5 : u.ulevel/3));
* which is clearer but less efficient and stands a vanishingly
* small chance of overflowing tmp
*/
}
int
rnz(i)
int i;
{
#ifdef LINT
int x = i;
int tmp = 1000;
#else
register long x = i;
register long tmp = 1000;
#endif
tmp += rn2(1000);
tmp *= rne(4);
if (rn2(2)) { x *= tmp; x /= 1000; }
else { x *= 1000; x /= tmp; }
return((int)x);
}
#endif /* OVLB */
/*rnd.c*/