// Parses a decomposition given the filename of the decomposition and the graph files.
public static Decomposition ParseDecomposition(string decompositionFilename, string graphFilename)
{
Graph graph = ParseGraph(graphFilename);
StreamReader sr = new StreamReader(decompositionFilename);
string line;
Tree tree = new Tree();
// Each line is simply an integer, which is the sequence of the linear decomposition
while ((line = sr.ReadLine()) != null)
{
// Skip comments
if (line.StartsWith("c ")) continue;
string[] s = line.Trim().Split(' ');
BitSet node = new BitSet(0, graph.Size);
foreach (string vertex in s)
node.Add(int.Parse(vertex) - 1); // -1 because internally we work with [0,...,n)
tree.Insert(node);
}
return new Decomposition(graph, tree);
}
// Retreives the actual ordering of a certain ordering that will not validate our bound
private static Tree RetrieveTree(Graph graph)
{
Tree tree = new Tree();
Queue<BitSet> queue = new Queue<BitSet>();
queue.Enqueue(graph.Vertices);
while (queue.Count != 0)
{
BitSet A = queue.Dequeue();
tree.Insert(A);
if (OptimalChild[A].IsEmpty) continue;
queue.Enqueue(OptimalChild[A]);
queue.Enqueue(A - OptimalChild[A]);
}
return tree;
}