public Varset Add(Varset varset)
{
Varset cp = new Varset(this);
Varset zero = new Varset(0);
cp.AlignLength(varset);
while (!varset.Equals(zero))
{
Varset tmp = cp.And(varset).LeftShift(1);
cp = cp.Xor(varset);
varset = tmp;
}
return cp;
}
public Varset NextPermutation()
{
Varset vs = new Varset(this);
Varset one = new Varset(0);
one.Set(0, true);
Varset tmp = vs.Or(vs.Subtract(one)).StaticAdd(one);
Varset nextVariables = tmp.Or(tmp.And(tmp.Not().StaticAdd(one)).Divide(vs.And(vs.Not().StaticAdd(one))).RightShift(1).Subtract(one));
return nextVariables;
}
public void Prune(DoubleMap cache)
{
List<KeyValuePair<ulong, double>> pairs = new List<KeyValuePair<ulong, double>>();
foreach (KeyValuePair<ulong, double> kvp in cache)
{
pairs.Add(kvp);
}
pairs.Sort(Comparison);
// keep track of the ones that have been pruned
BitArray prunedSet = new BitArray(pairs.Count);
for (int i = 0; i < pairs.Count; i++)
{
if (prunedSet.Get(i))
{
continue;
}
Varset pi = new Varset(pairs[i].Key);
// make sure this variable set is not in an incomplete last layer
if (pi.Cardinality() > highestCompletedLayer)
{
prunedSet.Set(i, true);
continue;
}
for (int j = i + 1; j < pairs.Count; j++)
{
if (prunedSet.Get(j))
{
continue;
}
// check if parents[i] is a subset of parents[j]
Varset pj = new Varset(pairs[j].Key);
if (pi.And(pj).Equals(pi)) // 部分集合かどうかの判定
{
// then we can prune pj
prunedSet.Set(j, true);
cache.Remove(pj.ToULong());
}
}
}
}
