public IEnumerable <BottlesState> GetStates(BottlesState currentState)
{
var options = new List <BottlesState>();
// Bottle 1 --> Bottle 2
if (currentState.Bottle1 > 0 && currentState.Bottle2 < _bottle2Max)
{
int bottle2 = currentState.Bottle2 + currentState.Bottle1;
var overflow = bottle2 - _bottle2Max;
// Om vi inte får plats, låt det överflödiga ligga kvar
int bottle1 = overflow > 0 ? overflow : 0;
// Om vi inte får plats, fyll flaskan.
bottle2 = bottle2 > _bottle2Max ? _bottle2Max : bottle2;
options.Add(new BottlesState(bottle1, bottle2));
}
// Bottle 2 --> Bottle 1
if (currentState.Bottle2 > 0 && currentState.Bottle1 < _bottle1Max)
{
int bottle1 = currentState.Bottle1 + currentState.Bottle2;
var overflow = bottle1 - _bottle1Max;
// Om vi inte får plats, låt det överflödiga ligga kvar
int bottle2 = overflow > 0 ? System.Math.Abs(overflow) : 0;
// Om vi inte får plats, fyll flaskan.
bottle1 = bottle1 > _bottle1Max ? _bottle1Max : bottle1;
options.Add(new BottlesState(bottle1, bottle2));
}
// Bottle 1 --> Empty
if (currentState.Bottle1 > 0)
{
options.Add(new BottlesState(0, currentState.Bottle2));
}
// Bottle 2 --> Empty
if (currentState.Bottle2 > 0)
{
options.Add(new BottlesState(currentState.Bottle1, 0));
}
// Bottle 1 --> Fill
if (currentState.Bottle1 < _bottle1Max)
{
options.Add(new BottlesState(_bottle1Max, currentState.Bottle2));
}
// Bottle 2 --> Fill
if (currentState.Bottle2 < _bottle2Max)
{
options.Add(new BottlesState(currentState.Bottle2, _bottle2Max));
}
return(options);
}
public static IEnumerable <BottlesState> FindPath(BottleGraph map, BottlesState start, Func <BottlesState, bool> isDone)
{
var foundPath = new List <BottlesState>();
int nodesChecked = 0;
bool found = false;
var toVisit = new Queue <BottlesState> ();
toVisit.Enqueue(start);
var cameFrom = new Dictionary <Tuple <int, int>, BottlesState> ();
cameFrom.Add(Tuple.Create(start.Bottle1, start.Bottle2), null);
var costs = new Dictionary <Tuple <int, int>, int> ();
costs.Add(Tuple.Create(start.Bottle1, start.Bottle2), 0);
var foundGoal = toVisit.First();
while (toVisit.Count > 0)
{
var current = toVisit.Dequeue();
if (isDone(current))
{
found = true;
foundGoal = current;
break;
}
var neighbours = map.GetStates(current).ToArray();
foreach (var next in neighbours)
{
int newCost = costs[Tuple.Create(current.Bottle1, current.Bottle2)] + 1;
if (!costs.ContainsKey(Tuple.Create(next.Bottle1, next.Bottle2)) || newCost < costs [Tuple.Create(next.Bottle1, next.Bottle2)])
{
costs [Tuple.Create(next.Bottle1, next.Bottle2)] = newCost;
toVisit.Enqueue(next);
cameFrom [Tuple.Create(next.Bottle1, next.Bottle2)] = current;
}
}
nodesChecked++;
}
if (!found)
{
return(foundPath);
}
var reverseCurrent = foundGoal;
var path = new Queue <BottlesState> (new[] { reverseCurrent });
while (reverseCurrent != start)
{
reverseCurrent = cameFrom [Tuple.Create(reverseCurrent.Bottle1, reverseCurrent.Bottle2)];
path.Enqueue(reverseCurrent);
}
foundPath = path.Reverse().ToList();
return(foundPath);
}
