maart@cs.vu.nl (Maarten Litmaath) (08/30/90)
Thanks to Icarus Sparry <I.Sparry@gdt.bath.ac.uk> for pointing out the
erroneous calls to free().
: This is a shar archive. Extract with sh, not csh.
: This archive ends with exit, so do not worry about trailing junk.
: --------------------------- cut here --------------------------
PATH=/bin:/usr/bin:/usr/ucb
echo Extracting 'perm.c'
sed 's/^X//' > 'perm.c' << '+ END-OF-FILE ''perm.c'
Xint perm(n, nullperm, length, dest)
Xlong n;
Xchar *nullperm, *dest;
Xint length;
X{
X long f;
X int d;
X char *orig, *p, *q, *r, *malloc();
X
X if (!(orig = p = malloc(length)))
X return -1;
X
X strncpy(p, nullperm, length);
X
X for (d = --length, f = 1; d > 0; d--)
X f *= d;
X
X while (length > 0) {
X d = n / f;
X *dest++ = p[d];
X if (!d)
X p++;
X else
X for (q = p + d, r = q + 1; *q++ = *r++; )
X ;
X n -= f * d;
X f /= length--;
X }
X
X *dest++ = *p;
X *dest = '\0';
X
X free(orig);
X
X return 0;
X}
X
X
Xmain(argc, argv)
Xint argc;
Xchar **argv;
X{
X char buf[32];
X long atol();
X
X if (argc > 2) {
X perm(atol(argv[1]), argv[2], strlen(argv[2]), buf);
X printf("%s\n", buf);
X }
X}
+ END-OF-FILE perm.c
chmod 'u=rw,g=r,o=r' 'perm.c'
set `wc -c 'perm.c'`
count=$1
case $count in
661) :;;
*) echo 'Bad character count in ''perm.c' >&2
echo 'Count should be 661' >&2
esac
echo Extracting 'perm_number.c'
sed 's/^X//' > 'perm_number.c' << '+ END-OF-FILE ''perm_number.c'
Xlong perm_number(s, nullperm, n)
Xchar *s, *nullperm;
Xint n;
X{
X long number = 0;
X char *q, *r, *c_index, *orig, *t, *malloc(), *index();
X
X if (!(orig = t = malloc(n)))
X return -1;
X
X strncpy(t, nullperm, n);
X
X while (--n > 0) {
X if (!(c_index = index(t, *s++))) {
X number = -1;
X break;
X }
X number += c_index - t;
X number *= n;
X if (c_index == t)
X t++;
X else
X for (q = c_index, r = q + 1; *q++ = *r++; )
X ;
X }
X
X free(orig);
X
X return number;
X}
X
X
Xmain(argc, argv)
Xint argc;
Xchar **argv;
X{
X if (argc > 2)
X printf("%ld\n",
X perm_number(argv[1], argv[2], strlen(argv[2])));
X}
+ END-OF-FILE perm_number.c
chmod 'u=rw,g=r,o=r' 'perm_number.c'
set `wc -c 'perm_number.c'`
count=$1
case $count in
589) :;;
*) echo 'Bad character count in ''perm_number.c' >&2
echo 'Count should be 589' >&2
esac
exit 0
--
"What is a rabbit? A particle that makes special tracks in the snow!"
(Paul M. Koloc)