public SparseMatrix Solve()
{
N = Costs.RowCount;
ModifyInitialCosts();
var tasks = new Queue<SalesmanTask>();
tasks.Enqueue(new SalesmanTask());
do
{
var currTask = tasks.Dequeue();
var ap = PrepareAssignmentProblem(currTask);
var resultPath = ap.Solve();
if (ap.TotalCost >= Record)
continue;
var chains = GetChains(resultPath);
if (chains.Count == 0)
throw new ArithmeticException("Problem has no chains!");
if (chains.Count == 1)
{
AnswerFound = true;
Record = ap.TotalCost;
RecordChain = chains.First();
continue;
}
var shortestChain = chains.First();
foreach (var chain in chains.Skip(1))
{
if (chain.Count < shortestChain.Count)
{
shortestChain = chain;
}
}
for (int i = 0; i < shortestChain.Count - 1; i++)
{
var newTask = new SalesmanTask(currTask.InfiniteRoads);
newTask.AddInfiniteRoad(shortestChain[i], shortestChain[i + 1]);
tasks.Enqueue(newTask);
}
} while (tasks.Count != 0);
if (!AnswerFound)
throw new ArithmeticException("Problem has no chains!");
return BuildResult();
}
private AssingmentProblem PrepareAssignmentProblem(SalesmanTask task)
{
DenseMatrix newCosts = (DenseMatrix)Costs.Clone();
foreach (var infRoad in task.InfiniteRoads)
{
newCosts[infRoad.Item1, infRoad.Item2] = Double.PositiveInfinity;
}
var ap = new AssingmentProblem(newCosts);
return ap;
}
