static int
backtrack_leftmost(struct saucy *s)
{
int rep = find_representative(s->indmin, s->theta);
int repsize = s->thsize[rep];
int min = -1;
pick_all_the_pairs(s);
clear_undiffnons(s);
s->ndiffs = s->nundiffs = s->npairs = s->ndiffnons = 0;
if (repsize != s->right.clen[s->start[s->lev]]+1) {
min = theta_prune(s);
}
if (min == -1) {
multiply_index(s, repsize);
}
return min;
}
static void
backtrack(struct saucy_stats *stats)
{
int i, j, k, t, indx, lastnon;
/* Keep backtracking for a while */
do {
/* Back up from this spot to our ancestor with zeta */
for (--lev; lev > 0; --lev) {
BCLEAR(bit_fixed, fixed[lev]);
if (flag && (lev > anc)) continue;
break;
}
/* If we're at the top, quit */
if (!lev) return;
/* Update ancestor with zeta if we've rewound more */
if (anc > lev) {
anc = lev;
indmin = fixed[lev];
}
/* Recover the partition nest to this level */
for (i = j = cells = 0, lastnon = -1; i < n; j = ++i) {
/* Rewind ptn */
while (ptn[i] > lev) {
ptn[i] = n+1;
cfront[lab[i++]] = j;
}
/* We're at the end of a cell */
++cells;
if (i == j) continue;
/* Update lengths and fronts */
clen[j] = i-j;
cfront[lab[i]] = j;
/* Update the nonsingleton list */
prevnon[j] = lastnon;
nextnon[lastnon] = j;
lastnon = j;
}
/* Fix the end of the nonsingleton list */
prevnon[n] = lastnon;
nextnon[lastnon] = n;
/* If we're at our gca with zeta, orbit prune with theta */
if (lev == anc) theta_prune(); else orbit_prune();
/* Compute |Aut(G)| found so far */
if ((target_min == n+1) && (anc == lev)) {
indx = 0; i = start[lev] - 1;
/* Find factor */
do {
/* Find lab[i]'s minimum cell representative */
for (j = lab[++i]; j != theta[j]; j = theta[j]);
k = lab[i]; while (theta[k] != j) {
t = theta[k]; theta[k] = j; k = t;
}
/* If it is the fixed value, then increment */
if (j == indmin) ++indx;
} while (ptn[i] > lev);
/* Update size */
MULTIPLY(stats->grpsize_base, stats->grpsize_exp, indx);
}
}
/* Quit when there's something left in the target */
while (target_min == n+1);
}
