public Problem(int smallBucketCapacity, int bigBucketCapacity, int goalVolume)
{
_smallBucketCapacity = smallBucketCapacity;
_bigBucketCapacity = bigBucketCapacity;
_goalVolume = goalVolume;
_initialState = new ProblemState(smallBucketCapacity, bigBucketCapacity);
}
public string PathFromRoot()
{
HashSet <ProblemState> states = new HashSet <ProblemState> {
State
};
Node node = Parent;
while (node != null)
{
states.Add(node.State);
node = node.Parent;
}
states = states.Reverse().ToHashSet();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < states.Count; i++)
{
ProblemState nextState = states.ElementAt(i);
sb.Append(nextState);
if (i + 1 != states.Count)
{
sb.Append("->");
}
}
return(sb.ToString());
}
private static Node GetExcludedNode(ProblemState state)
{
ProblemState ps = new ProblemState(state);
ps.SmallBucket.FillUp();
ps.BigBucket.FillUp();
return(new Node(ps));
}
public static HashSet <Node> Expand(Node node)
{
HashSet <Node> successors = new HashSet <Node>();
ProblemState state = node.State;
if (state.SmallBucket.IsEmpty())
{
ProblemState ps = new ProblemState(node.State);
ps.SmallBucket.FillUp();
successors.Add(new Node(ps, node));
}
if (state.BigBucket.IsEmpty())
{
ProblemState ps = new ProblemState(node.State);
ps.BigBucket.FillUp();
successors.Add(new Node(ps, node));
}
if (!state.SmallBucket.IsEmpty())
{
ProblemState ps = new ProblemState(node.State);
ps.SmallBucket.Dump();
successors.Add(new Node(ps, node));
if (!state.BigBucket.IsFull())
{
ps = new ProblemState(node.State);
ps.SmallBucket.PourWaterInto(ps.BigBucket);
successors.Add(new Node(ps, node));
}
}
if (!state.BigBucket.IsEmpty())
{
ProblemState ps = new ProblemState(node.State);
ps.BigBucket.Dump();
successors.Add(new Node(ps, node));
if (!state.SmallBucket.IsFull())
{
ps = new ProblemState(node.State);
ps.BigBucket.PourWaterInto(ps.SmallBucket);
successors.Add(new Node(ps, node));
}
}
HashSet <Node> parentNodes = node.GetParentNodes();
successors.RemoveWhere(n => parentNodes.Contains(n) || Equals(n, GetExcludedNode(state)));
return(successors);
}
/// <summary>
/// Returns a boolean value whether specified state is the goal state
/// </summary>
public bool IsGoalState(ProblemState state)
{
if (Equals(state.SmallBucket.GetVolume(), _goalVolume))
{
return(true);
}
if (Equals(state.BigBucket.GetVolume(), _goalVolume))
{
return(true);
}
return(false);
}
public Node(ProblemState state)
: this(state, null)
{
}
public Node(ProblemState state, Node parent)
{
State = state ?? throw new ArgumentNullException(nameof(state));
Parent = parent;
}