static boolean
isstrong(graph *g, int n)
/* test if tournament g is strongly-connected
* This code is strictly for tournaments only.
*/
{
setword seen,expanded,toexpand,allbits;
int i;
allbits = ALLMASK(n);
seen = bit[0] | g[0];
expanded = bit[0];
while (seen != allbits && (toexpand = (seen & ~expanded))) /* not == */
{
i = FIRSTBITNZ(toexpand);
expanded |= bit[i];
seen |= g[i];
}
if (seen != allbits) return FALSE;
seen = (allbits ^ g[0]);
expanded = bit[0];
while (seen != allbits && (toexpand = (seen & ~expanded))) /* not == */
{
i = FIRSTBITNZ(toexpand);
expanded |= bit[i];
seen |= (g[i] ^ allbits);
}
return seen == allbits;
}
void
contract1(graph *g, graph *h, int v, int w, int n)
/* Contract distinct vertices v and w (not necessarily adjacent)
with result in h. No loops are created. */
{
int x,y;
setword bitx,bity,mask1,mask2;
int i;
if (w < v)
{
x = w;
y = v;
}
else
{
x = v;
y = w;
}
bitx = bit[x];
bity = bit[y];
mask1 = ALLMASK(y);
mask2 = BITMASK(y);
for (i = 0; i < n; ++i)
if (g[i] & bity)
h[i] = (g[i] & mask1) | bitx | ((g[i] & mask2) << 1);
else
h[i] = (g[i] & mask1) | ((g[i] & mask2) << 1);
h[x] |= h[y];
for (i = y+1; i < n; ++i) h[i-1] = h[i];
h[x] &= ~bitx;
}
static boolean
isconnected(graph *g, int n)
/* test if g is connected */
{
setword seen,expanded,toexpand,allbits;
int i;
allbits = ALLMASK(n);
expanded = bit[n-1];
seen = expanded | g[n-1];
while (seen != allbits && (toexpand = (seen & ~expanded))) /* not == */
{
i = FIRSTBITNZ(toexpand);
expanded |= bit[i];
seen |= g[i];
}
return seen == allbits;
}
void
delete1(graph *g, graph *h, int v, int n)
/* Delete vertex v from g, result in h */
{
setword mask1,mask2,gi;
int i;
mask1 = ALLMASK(v);
mask2 = BITMASK(v);
for (i = 0; i < v; ++i)
{
gi = g[i];
h[i] = (gi & mask1) | ((gi & mask2) << 1);
}
for (i = v; i < n-1; ++i)
{
gi = g[i+1];
h[i] = (gi & mask1) | ((gi & mask2) << 1);
}
}
long
cyclecount1(graph *g, int n)
/* The total number of cycles in g (assumed no loops), m=1 only */
{
setword body,nbhd;
long total;
int i,j;
body = ALLMASK(n);
total = 0;
for (i = 0; i < n-2; ++i)
{
body ^= bit[i];
nbhd = g[i] & body;
while (nbhd)
{
TAKEBIT(j,nbhd);
total += pathcount1(g,j,body,nbhd);
}
}
return total;
}
int
static main(int argc, char *argv[])
{
int i,j,bad;
setword w,ww;
printf("NAUTYVERSION=%s NAUTYVERSIONID=%d\n",
NAUTYVERSION,NAUTYVERSIONID);
printf("MAXN=%d MAXM=%d WORDSIZE=%d NAUTY_INFINITY=%d\n",
MAXN,MAXM,WORDSIZE,NAUTY_INFINITY);
printf("sizes: short=%d int=%d long=%d double=%d\n",
(int)sizeof(short),(int)sizeof(int),(int)sizeof(long),
(int)sizeof(double));
printf("sizes: boolean=%d setword=%d\n",
(int)sizeof(boolean),(int)sizeof(setword));
printf("CLZ=%d,%d,%d\n",HAVE_CLZ,HAVE_CLZL,HAVE_CLZLL);
#if SIZEOF_LONGLONG > 0
printf("sizeof(long long)=%d\n",sizeof(long long));
#endif
printf("defined:");
#ifdef __STDC__
printf(" __STDC__");
#endif
#ifdef BIGNAUTY
printf(" BIGNAUTY(obsolete!)");
#endif
#ifdef SYS_UNIX
printf(" SYS_UNIX");
#endif
#ifdef SYS_CRAY
printf(" SYS_CRAY");
#endif
#ifdef SETWORD_SHORT
printf(" SETWORD_SHORT");
#endif
#ifdef SETWORD_INT
printf(" SETWORD_INT");
#endif
#ifdef SETWORD_LONG
printf(" SETWORD_LONG");
#endif
#ifdef SETWORD_LONGLONG
printf(" SETWORD_LONGLONG");
#endif
printf("\n");
bad = 0;
if (8*sizeof(setword) != WORDSIZE)
{
printf("\n ***** NOTE: WORDSIZE mismatch *****\n\n");
++bad;
}
for (i = 0; i < WORDSIZE; ++i)
{
w = ALLMASK(i);
if (POPCOUNT(w) != i)
{
printf("\n ***** POPCOUNT(ALLMASK) error %d *****\n\n",i);
++bad;
}
}
for (i = 0; i < WORDSIZE; ++i)
{
w = BITMASK(i);
if (POPCOUNT(w) != WORDSIZE-i-1)
{
printf("\n ***** POPCOUNT(BITMASK) error %d *****\n\n",i);
++bad;
}
}
for (i = 0; i < WORDSIZE; ++i)
if (POPCOUNT(ALLMASK(i)) != i)
{
printf("\n ***** POPCOUNT(ALLMASK) error %d *****\n\n",i);
++bad;
}
for (i = 0; i < WORDSIZE; ++i)
if (FIRSTBIT(BITT[i]) != i)
{
printf("\n ***** FIRSTBIT(BITT) error %d *****\n\n",i);
++bad;
}
if (FIRSTBIT((setword)0) != WORDSIZE)
{
printf("\n ***** FIRSTBIT(0) error *****\n\n");
++bad;
}
for (i = 0; i < WORDSIZE; ++i)
if (POPCOUNT(BITT[i]) != 1)
{
printf("\n ***** POPCOUNT(BITT) error %d *****\n\n",i);
++bad;
}
for (i = 0; i < WORDSIZE; ++i)
{
w = 0;
for (j = 1; j <= WORDSIZE; ++j)
{
w |= BITT[(j*97+i)%WORDSIZE];
if (POPCOUNT(w) != j)
{
printf("\n ***** POPCOUNT(w) error %d %d *****\n\n",i,j);
++bad;
}
}
}
if (!bad) printf("\nNo errors found\n");
else printf("\nXXXXXXX %d errors found XXXXXXX\n",bad);
exit(0);
}
int
conncontent(graph *g, int m, int n)
/* number of connected spanning subgraphs with an even number
of edges minus the number with an odd number of edges */
{
graph h[WORDSIZE];
setword gj;
int i,j,v1,v2,x,y;
int minv,mindeg,deg,goodv;
long ne;
if (m > 1) ABORT("conncontent only implemented for m=1");
/* First handle tiny graphs */
if (n <= 3)
{
if (n == 1) return 1;
if (n == 2) return (g[0] ? -1 : 0);
if (!g[0] || !g[1] || !g[2]) return 0; /* disconnected */
if (g[0]^g[1]^g[2]) return 1; /* path */
return 2; /* triangle */
}
/* Now compute
ne = number of edges
mindeg = minimum degree
minv = a vertex of minimum degree
goodv = a vertex with a clique neighbourhood (-1 if none)
*/
mindeg = n;
ne = 0;
goodv = -1;
for (j = 0; j < n; ++j)
{
gj = g[j];
deg = POPCOUNT(gj);
ne += deg;
if (deg < mindeg)
{
mindeg = deg;
minv = j;
if (deg == 1) goodv = j;
}
if (deg >= 3 && deg <= 4 && goodv < 0)
{
while (gj)
{
TAKEBIT(i,gj);
if (gj & ~g[i]) break;
}
if (!gj) goodv = j;
}
}
ne /= 2;
/* Cases of isolated vertex or tree */
if (mindeg == 0) return 0;
#if 0
if (mindeg == 1 && ne == n-1)
{
if (isconnected1(g,n)) return ((n&1) ? 1 : -1);
else return 0;
}
#endif
/* Cases of clique and near-clique */
if (mindeg == n-1)
{
j = -1;
for (i = 2; i < n; ++i) j *= -i;
return j;
}
if (mindeg == n-2 && n < 16)
{
if (!knm_computed)
{
knm_computed = TRUE;
knm[1][0] = 1;
for (i = 2; i < 16; ++i)
{
knm[i][0] = -knm[i-1][0] * (i-1);
for (j = 1; j+j <= i; ++j)
knm[i][j] = knm[i][j-1] + knm[i-1][j-1];
}
}
return knm[n][(n*n-n)/2-ne];
}
/* Case of vertex with clique neighbourhood */
if (goodv >= 0)
{
delete1(g,h,goodv,n);
return -POPCOUNT(g[goodv]) * conncontent(h,m,n-1);
}
/* Case of minimum degree 2 */
if (mindeg == 2)
{
x = FIRSTBIT(g[minv]);
y = FIRSTBIT(g[minv]^bit[x]);
if (x > minv) --x;
if (y > minv) --y;
delete1(g,h,minv,n);
v1 = conncontent(h,m,n-1);
if (h[x] & bit[y]) return -2*v1; /* adjacent neighbours */
h[x] |= bit[y];
h[y] |= bit[x];
v2 = conncontent(h,m,n-1);
return -v1 - v2;
}
/* Case of more than 2/3 dense but not complete */
if (3*ne > n*n-n)
{
j = FIRSTBIT(g[minv] ^ bit[minv] ^ ALLMASK(n)); /* non-neighbour */
g[minv] ^= bit[j];
g[j] ^= bit[minv];
v1 = conncontent(g,m,n);
g[minv] ^= bit[j];
g[j] ^= bit[minv];
contract1(g,h,minv,j,n);
v2 = conncontent(h,m,n-1);
return v1 + v2;
}
/* All remaining cases */
j = FIRSTBIT(g[minv]); /* neighbour */
g[minv] ^= bit[j];
g[j] ^= bit[minv];
v1 = conncontent(g,m,n);
g[minv] ^= bit[j];
g[j] ^= bit[minv];
contract1(g,h,minv,j,n);
v2 = conncontent(h,m,n-1);
return v1 - v2;
}