public PartialSolution(PartialSolution parent)
{
G = parent.G;
VertexSubset = (int[])parent.VertexSubset.Clone();
SeparatorSubset = (int[])parent.SeparatorSubset.Clone();
SeparatorSize = parent.SeparatorSize;
DepthBelow = parent.DepthBelow;
}
public PartialSolution AddVertex(Vertex v)
{
PartialSolution result = new PartialSolution(this);
if (Contains(v))
{
return(result);
}
result.VertexSubset[v.Id / 32] |= (1 << (v.Id % 32));
result.DepthBelow++;
result.RootVertexID = v.Id;
//result.Child = this;
result.Left = this;
if (IsSep(v))
{
result.SeparatorSubset[v.Id / 32] &= ~(1 << (v.Id % 32));
result.SeparatorSize--;
}
foreach (Vertex u in v.Nb)
{
if (!Contains(u) && !IsSep(u))
{
if (u.Adj.Count == 1 && v.Adj.Count != 1)
{
return(null);
}
result.SeparatorSize++;
result.SeparatorSubset[u.Id / 32] |= 1 << (u.Id % 32);
}
}
if (result.LowerBound > Graph.UB)
{
return(null);
}
return(result);
}
public PartialSolution Join(PartialSolution other)
{
int newSepSize = 0;
for (int i = 0; i < VertexSubset.Length; i++)
{
if ((this.VertexSubset[i] & other.VertexSubset[i]) != 0)
{
return(null);
}
newSepSize += (this.SeparatorSubset[i] | other.SeparatorSubset[i]).BitCount();
}
if (newSepSize == SeparatorSize + other.SeparatorSize)
{
return(null);
}
if (newSepSize + Math.Max(DepthBelow, other.DepthBelow) > Graph.UB)
{
return(null);
}
PartialSolution result = new PartialSolution(other);
result.Left = this;
result.Right = other;
// Copy subsets
for (int i = 0; i < VertexSubset.Length; i++)
{
result.VertexSubset[i] |= this.VertexSubset[i];
}
for (int i = 0; i < SeparatorSubset.Length; i++)
{
result.SeparatorSubset[i] |= this.SeparatorSubset[i];
}
result.SeparatorSize = newSepSize;
result.DepthBelow = Math.Max(DepthBelow, other.DepthBelow);
foreach (Vertex v in result.Separator)
{
if (!v.Nb.Any((u) => !result.Contains(u) && !result.IsSep(u)))
{
PartialSolution resultChild = new PartialSolution(result);
resultChild.RootVertexID = result.RootVertexID;
resultChild.Left = result.Left; resultChild.Right = result.Right;
result.Left = resultChild; result.Right = null;
result.RootVertexID = v.Id;
result.SeparatorSubset[v.Id / 32] &= ~(1 << (v.Id % 32));
result.VertexSubset[v.Id / 32] |= 1 << (v.Id % 32);
result.SeparatorSize--;
result.DepthBelow++;
}
}
return(result);
}
public bool TrySolve()
{
PriorityQueue <PartialSolution> q = new PriorityQueue <PartialSolution>();
HashSet <PartialSolution> processed = new HashSet <PartialSolution>();
foreach (Vertex v in Vertices)
{
PartialSolution ps = new PartialSolution(this);
ps = ps.AddVertex(v);
if (ps == null)
{
continue;
}
q.Enqueue(ps, ps.DepthBelow);
}
while (q.Count > 0)// && sw.ElapsedMilliseconds < 1000 * 60 * 3)
{
PartialSolution ps = q.Dequeue();
if (processed.Contains(ps))
{
continue;
}
int count = ps.Vertices.Count() + ps.Separator.Count();
if (count == Vertices.Length)
{
//Console.WriteLine("Solution: " + ps.LowerBound);
//Console.WriteLine();
PartialSolution result = ps;
foreach (Vertex v in ps.Separator)
{
result = result.AddVertex(v);
throw new Exception("Unexpected condition");
}
result.Print();
return(true);
}
foreach (Vertex v in ps.Separator)
{
PartialSolution newPS = ps.AddVertex(v);
if (newPS == null)
{
continue;
}
q.Enqueue(newPS, newPS.DepthBelow);
int scount = newPS.Separator.Count();
PartialSolution key = new PartialSolution(this);
key.VertexSubset = newPS.SeparatorSubset;
}
List <PartialSolution> toAdd = new List <PartialSolution>();
foreach (PartialSolution mergeCandidate in processed)
{
PartialSolution newPS = ps.Join(mergeCandidate);
if (newPS == null)
{
continue;
}
toAdd.Add(newPS);
}
foreach (PartialSolution newPS in toAdd)
{
q.Enqueue(newPS, newPS.DepthBelow);
int scount = newPS.Separator.Count();
PartialSolution key = new PartialSolution(this);
key.VertexSubset = newPS.SeparatorSubset;
}
processed.Add(ps);
}
/*if(sw.ElapsedMilliseconds >= 1000 * 60 * 3)
* {
* Console.WriteLine("Time out at: " + UB);
*
* return true;
* }*/
return(false);
}