public static long Parent(BitGraph_long g, long set, long LFMIS, long S)
{
var a = LFMIS & ~S;
var bit = a & -a;
var v = bit.Extract();
var N = g.NeighborsInSet(v, S);
return(LexicographicallyFirstContaining(g, set, (S | bit) ^ N));
}
public static List <long> GenerateMaximalIndependentSubsets(BitGraph_long g, long set)
{
var d = new int[64];
var n = set.PopulationCountDense();
var D = new long[n];
var q = set;
while (q != 0)
{
var bit = q & -q;
var v = bit.Extract();
d[v] = g.DegreeInSet(v, set);
D[d[v]] |= bit;
q ^= bit;
}
var bits = new long[n];
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
if (D[j] != 0)
{
var bit = D[j] & -D[j];
bits[n - 1 - i] = bit;
var v = bit.Extract();
q = g.NeighborsInSet(v, set);
while (q != 0)
{
var b = q & -q;
var x = b.Extract();
D[d[x]] ^= b;
d[x]--;
D[d[x]] |= b;
q ^= b;
}
set ^= bit;
D[j] ^= bit;
break;
}
}
}
return(GenerateMaximalIndependentSubsets(g, bits));
}
public static long LexicographicallyFirstContaining(BitGraph_long g, long set, long S)
{
set ^= S;
while (set != 0)
{
var bit = set & -set;
var v = bit.Extract();
if (g.NeighborsInSet(v, S) == 0)
{
S |= bit;
}
set ^= bit;
}
return(S);
}
public static bool IsSubsetTwoColorable(BitGraph_long g, long set)
{
var c = new int[g.N];
var q = new int[g.N];
var leftover = set;
var s = 0;
while (leftover != 0)
{
var r = leftover.LeastSignificantBit();
q[s] = r;
c[r] = 1;
var e = s;
while (s <= e)
{
var v = q[s++];
var n = g.NeighborsInSet(v, set);
while (n != 0)
{
var bit = n & -n;
var w = bit.Extract();
if (c[w] == 0)
{
q[++e] = w;
c[w] = 3 - c[v];
}
else if (c[w] != 3 - c[v])
{
return(false);
}
n ^= bit;
}
leftover ^= (1L << v);
}
}
return(true);
}
public static long Later(BitGraph_long g, long set, long LFMIS, int v)
{
var q = g.NeighborsInSet(v, set ^ LFMIS);
var earlier = ((1L << v) - 1) & LFMIS;
var later = 0L;
while (set != 0)
{
var bit = q & -q;
var w = bit.Extract();
if (g.NeighborsInSet(w, earlier) == 0)
{
later |= bit;
}
q ^= bit;
}
return(later);
}
static List <long> GenerateMaximalIndependentSubsets(BitGraph_long g, long[] bits)
{
var mis = new List <long>(8);
mis.Add(0L);
var earlier = 0L;
for (int j = 0; j < bits.Length; j++)
{
var bit = bits[j];
var v = bit.Extract();
var count = mis.Count;
for (int i = 0; i < count; i++)
{
var m = mis[i];
var N = g.NeighborsInSet(v, m);
if (N == 0)
{
mis[i] |= bit;
}
else
{
var mp = m & ~N;
var mpp = mp | bit;
var q = N;
var l = earlier & ~mpp;
while (q != 0)
{
var b = q & -q;
var w = b.Extract();
var qq = g.NeighborsInSet(w, l);
while (qq != 0)
{
var bb = qq & -qq;
var z = bb.Extract();
if (g.NeighborsInSet(z, mpp) == 0)
{
goto skip;
}
qq ^= bb;
}
q ^= b;
}
var X = g.NeighborsInSet(v, earlier);
q = X & ~N;
while (q != 0)
{
var b = q & -q;
var w = b.Extract();
if (g.NeighborsInSet(w, mp) != 0)
{
X ^= b;
}
q ^= b;
}
if (X != N)
{
var Z = 0L;
while (Z < N)
{
Z = (Z - X) & X;
if ((Z & N) == Z)
{
continue;
}
if (!g.IsIndependent(Z))
{
continue;
}
var mm = mp | Z;
l = earlier & ~mm;
q = N & ~Z;
while (q != 0)
{
var b = q & -q;
var w = b.Extract();
var qq = g.NeighborsInSet(w, l);
while (qq != 0)
{
var bb = qq & -qq;
var z = bb.Extract();
if (g.NeighborsInSet(z, mm) == 0)
{
goto notMaximal;
}
qq ^= bb;
}
q ^= b;
}
goto skip;
notMaximal :;
}
}
mis.Add((m | bit) & ~N);
skip :;
}
}
earlier |= bit;
}
return(mis);
}
