async private Task <List <StateView> > MakeResult(CancellationToken cancelToken)
{
return(await Task.Run(() =>
{
List <StateView> resultCollection = null;
//Do not use this approach in enterprise!.
StateFactory.SetNumberOfEach(NumberOfEach);
var p = new Problem(StateFactory.Make(NumberOfEach, NumberOfEach, BoatState.Left, 0),
StateFactory.Make(0, 0, BoatState.Right, 0), BoatSize);
var result = Algorithm.UniformCostSearch(p, cancelToken);
if (result != null)
{
Stack <State> stack = new Stack <State>();
while (result != null)
{
stack.Push(result);
result = result.PrevState;
}
cancelToken.ThrowIfCancellationRequested();
resultCollection = new List <StateView>(stack.Count);
int n = 0;
foreach (var state in stack)
{
resultCollection.Add(new StateView(state, n++));
}
return resultCollection;
}
return new List <StateView>();
}, cancelToken));
}
public IEnumerable <State> GetSuccessors(State state)
{
var result = new List <State>();
//loop through all possible combinations
for (int nMiss = 0; nMiss <= _boatSize; nMiss++)
{
for (int nCan = 0; nCan <= _boatSize; nCan++)
{
if (nMiss == 0 && nCan == 0)
{
continue;
}
if (nMiss + nCan > _boatSize)
{
break;
}
var BoatDirection = state.BoatOnTheSide.AsMultiplier();
var s = StateFactory.Make(
state.Missionaries + nMiss * BoatDirection,
state.Cannibals + nCan * BoatDirection,
state.BoatOnTheSide.Inverse(),
state,
state.StateLevel + 1);
if (s.IsValidState())
{
result.Add(s);
}
}
}
return(result);
}
