public static LinkedList<Node> BuildNodePath(Node Start, Node Goal, long NodesCountInSystem)
{
int expandedNodesCount = 0;
int nodesInNowList = 0;
int depthLimit = 0;
bool found = false;
TreeNode start = new TreeNode(Start);
TreeNode goal = new TreeNode(Goal);
LinkedList<TreeNode> toExpand = new LinkedList<TreeNode>();
Dictionary<long, TreeNode> discoveredNodes = new Dictionary<long, TreeNode>();
toExpand.AddFirst(start);
discoveredNodes.Add(start.Node.Id, start);
while (!found)
{
toExpand = FringeSearchIteration(goal, toExpand, discoveredNodes, depthLimit, ref found, ref expandedNodesCount);
nodesInNowList += toExpand.Count;
depthLimit++;
if (discoveredNodes.Count == NodesCountInSystem)
throw new PathNotFoundException("Path not found!");
}
Console.WriteLine("Expanded {0} nodes", expandedNodesCount);
Console.WriteLine("Nodes in now list: {0}", nodesInNowList);
return createPath(goal, start);
}
public static Dictionary<AbstractState, Node> CreateGraph(Node root, params AbstractAction[] actions)
{
Dictionary<AbstractState, Node> uniqeNodes = new Dictionary<AbstractState, Node>();
uniqeNodes.Add(root.State, root);
Queue<Node> queue = new Queue<Node>();
queue.Enqueue(root);
while (queue.Count > 0)
{
Node curNode = queue.Dequeue();
foreach (var action in actions)
{
AbstractState state = action.execute(curNode);
if (state != null)
if (!uniqeNodes.ContainsKey(state))
{
Node newNode = new Node(state);
curNode.Children.Add(new Tuple<Node, AbstractAction>(newNode, action));
uniqeNodes.Add(state, newNode);
queue.Enqueue(newNode);
}
else
{
curNode.Children.Add(new Tuple<Node, AbstractAction>(uniqeNodes[state], action));
}
}
}
return uniqeNodes;
}
public override IList<AbstractState> GetNextStates(Node node)
{
IList<AbstractState> states = new List<AbstractState>();
foreach (var action in actions)
{
AbstractState state = action.execute(node);
if (state != null && state is TilesState)
states.Add(state);
}
return states;
}
public static LinkedList<Node> BuildNodePathUsingAStarWithoutSystem(Node Start, Node Goal, HeuristicCalculator Calculator, NextStatesProvider Provider)
{
int expandedNodesCount = 0;
bool found = false;
TreeNode start = new TreeNode(Start);
TreeNode goal = new TreeNode(null);
var toExpand = new C5.IntervalHeap<TreeNode>(new TreeNodeCostComparer());
var discoveredTreeNodes = new Dictionary<int, TreeNode>();
start.Cost = Calculator.Calculate(Start.State, Goal.State);
toExpand.Add(start);
discoveredTreeNodes.Add(start.Node.State.GetHashCode(), start);
while (toExpand.Count > 0)
{
TreeNode Current = toExpand.FindMin();
toExpand.DeleteMin();
if (Current.Node.State.Equals(Goal.State))
{
goal = Current;
found = true;
break;
}
expandedNodesCount++;
foreach (var nextNode in Provider.GetNodesWithNextStates(Current.Node))
{
double Cost = Calculator.Calculate(nextNode.State, Goal.State);
if (!discoveredTreeNodes.ContainsKey(nextNode.State.GetHashCode()))
{
TreeNode Tem = new TreeNode(nextNode, Current, Current.Cost + Cost);
Current.Children.AddLast(Tem);
discoveredTreeNodes.Add(nextNode.State.GetHashCode(), Tem);
toExpand.Add(Tem);
}
else
{
CheckIfBetterPathWasFound(discoveredTreeNodes, Current, nextNode, Cost);
}
}
}
Console.WriteLine("Expanded {0} nodes", expandedNodesCount);
if (!found)
throw new PathNotFoundException("Path not found!");
return createPath(goal, start);
}
public override IList<Node> GetNodesWithNextStates(Node node)
{
IList<Node> nodes = new List<Node>();
foreach (var action in actions)
{
AbstractState state = action.execute(node);
if (state != null && state is TilesState)
{
Node newNode = new Node(state);
node.Children.Add(Tuple.Create(newNode, action));
nodes.Add(newNode);
}
}
return nodes;
}
private static Dictionary<long, Node> createNodes(string FileName, char separator)
{
var nodes = new Dictionary<long, Node>();
var lines = readLines(FileName);
foreach (var line in lines)
{
var coords = line.Split(separator);
var val = Convert.ToDouble(coords[0]);
var state = new MazeState(Convert.ToDouble(coords[0]), Convert.ToDouble(coords[1]));
var node = new Node(state);
nodes.Add(node.Id, node);
}
return nodes;
}
public override AbstractState execute(Node node)
{
if (!(node.State is TilesState))
throw new InvalidCastException();
TilesState state = node.State as TilesState;
int[,] tiles = state.GetTiles();
int rowCoord = state.EmptyTileRowCoord;
int colCoord = state.EmptyTileColumnCoord;
if (CanShift(ShiftDirectionEnum.DOWN, rowCoord, colCoord))
{
tiles[rowCoord, colCoord] = tiles[rowCoord + 1, colCoord];
tiles[rowCoord + 1, colCoord] = 0;
state = new TilesState(tiles);
return state;
}
return null;
}
private static void CheckIfBetterPathWasFound(Dictionary<int, TreeNode> discoveredTreeNodes, TreeNode Current, Node nextNode, double Cost)
{
var updateCandidate = discoveredTreeNodes[nextNode.State.GetHashCode()];
if (updateCandidate.Cost > Current.Cost + Cost)
{
var costDifference = updateCandidate.Cost - (Current.Cost + Cost);
Current.Children.AddLast(updateCandidate);
updateCandidate.Parent.Children.Remove(updateCandidate);
updateCandidate.Parent = Current;
updateCandidate.Cost = Current.Cost + Cost;
var candidateChildren = new LinkedList<TreeNode>(updateCandidate.Children);
while (candidateChildren.Count > 0)
{
var child = candidateChildren.First();
candidateChildren.RemoveFirst();
foreach (var item in child.Children)
candidateChildren.AddLast(item);
child.Cost -= costDifference;
}
}
}
public abstract override AbstractState execute(Node node);
public abstract AbstractState execute(Node node);
static void Main(string[] args)
{
int[,] rootMatrix = new int[,] {{7, 2, 4 },{5, 0, 6 },{8, 3, 1 }};
TilesState rootState = new TilesState(rootMatrix);
IList<AbstractAction> actions = new List<AbstractAction>();
actions.Add(new ShiftEmptyTileLeftAction());
actions.Add(new ShiftEmptyTileRightAction());
actions.Add(new ShiftEmptyTileUpAction());
actions.Add(new ShiftEmptyTileDownAction());
Node root = new Node(rootState);
HeuristicCalculator calculator = new TilesHeuristicCalculator();
NextStatesProvider provider = new NextTileStatesProvider(actions);
// Console.WriteLine(calculator.Calculate(rootState, new TilesState(new int[,] { { 0, 1, 2 }, { 3, 4, 5 }, { 6, 7, 8 } })));
try
{
var path = PathBuilder.BuildNodePathUsingAStarWithoutSystem(root, new Node(new TilesState(new int[,] { { 0, 1, 2 }, { 3, 4, 5 }, { 6, 7, 8 } })), calculator, provider);
//foreach (var node in path)
// Console.WriteLine(node);
foreach (var action in PathTransformer.TransformNodePathToActionPath(path))
Console.WriteLine(action);
}
catch (PathNotFoundException ex) { Console.WriteLine(ex.Message); }
/*
var uniqueNodes = NodeGraphFactory.CreateGraph(root, actions.ToArray());
//Console.WriteLine(uniqueNodes.Count);
try
{
var path = PathBuilder.BuildNodePath(root, new Node(new TilesState(new int[,] { { 0, 1, 2 }, { 3, 4, 5 }, { 6, 7, 8 } })), uniqueNodes.Count);
foreach (var action in PathTransformer.TransformNodePathToActionPath(path))
Console.WriteLine(action);
}
catch (PathNotFoundException ex) { Console.WriteLine(ex.Message); }
Console.WriteLine("\n-----------\n");
try
{
var path = PathBuilder.BuildNodePath(root, new Node(new TilesState(new int[,] { { 8, 0, 6 }, { 5, 4, 7 }, { 2, 3, 1 } })), uniqueNodes.Count);
foreach (var action in PathTransformer.TransformNodePathToActionPath(path))
Console.WriteLine(action);
}
catch (PathNotFoundException ex) { Console.WriteLine(ex.Message); }
Console.WriteLine("\n-----------\n");
try
{
var path = PathBuilder.BuildNodePath(root, new Node(new TilesState(new int[,] { { 1, 2, 3 }, { 8, 0, 4 }, { 7, 6, 5 } })), uniqueNodes.Count);
foreach (var action in PathTransformer.TransformNodePathToActionPath(path))
Console.WriteLine(action);
}
catch (PathNotFoundException ex) { Console.WriteLine(ex.Message); }
*/
Console.ReadKey();
}
public override AbstractState execute(Node node)
{
throw new NotImplementedException();
}
public abstract IList<Node> GetNodesWithNextStates(Node node);
public abstract IList<AbstractState> GetNextStates(Node node);
