private static void MakeComponents()
{
var A = new WeightedGraphNode <char>('A');
var B = new WeightedGraphNode <char>('B');
var C = new WeightedGraphNode <char>('C');
var D = new WeightedGraphNode <char>('D');
var E = new WeightedGraphNode <char>('E');
var F = new WeightedGraphNode <char>('F');
A.AddMutualNeighbor(B);
A.AddMutualNeighbor(C);
B.AddMutualNeighbor(C);
D.AddMutualNeighbor(E);
var G = new Graph <char>(A, B, C, D, E, F);
var components = G.FindConnectedComponents();
foreach (var component in components)
{
component.PrintNodes();
Console.WriteLine();
}
}
static void MakeWeightedGraph()
{
//Vertex Set
WeightedGraphNode <char> A = new WeightedGraphNode <char>('A');
WeightedGraphNode <char> B = new WeightedGraphNode <char>('B');
WeightedGraphNode <char> C = new WeightedGraphNode <char>('C');
WeightedGraphNode <char> D = new WeightedGraphNode <char>('D');
WeightedGraphNode <char> E = new WeightedGraphNode <char>('E');
WeightedGraphNode <char> F = new WeightedGraphNode <char>('F');
WeightedGraphNode <char> G = new WeightedGraphNode <char>('G');
//Edge Set
A.AddMutualNeighbor(B, 4);
A.AddMutualNeighbor(G, 2);
A.AddMutualNeighbor(D, 1);
B.AddMutualNeighbor(D, 6);
B.AddMutualNeighbor(G, 9);
C.AddMutualNeighbor(D, 6);
C.AddMutualNeighbor(E, 4);
E.AddMutualNeighbor(F, 3);
F.AddMutualNeighbor(G, 5);
GraphNode <char>[] nodes = { A, B, C, D, E, F, G };
Graph <char> a_graph = new Graph <char>(nodes);
Console.WriteLine("Finding the shorting path between B and E");
var path = a_graph.RunDijkstra(B, E);
if (path == null)
{
Console.WriteLine("Nope :(");
}
else
{
Console.WriteLine("\n The shortest path has weight {0} ", path.PathWeightToHere);
//use a stack to figure out the order to take
var reverse_backtracking = new Stack <NodePath <char> >();
while (path != null)
{
reverse_backtracking.Add(path);
path = (WeightedNodePath <char>)path.Parent;
}
while (!reverse_backtracking.IsEmpty())
{
var top = reverse_backtracking.Pop();
Console.Write("{0}", top.Node.GetValue());
if (reverse_backtracking.Count > 0)
{
Console.Write(" -> ");
}
}
Console.WriteLine("\n-------------------------------\n");
}
}
public static WeightedGraph <double> GetWeightedGraph(ICellMap map, NeighbourMode neighbourMode)
{
WeightedGraphNode <double>[,] nodes = new WeightedGraphNode <double> [map.Width, map.Height];
for (int x = 0; x < map.Width; x++)
{
for (int y = 0; y < map.Height; y++)
{
if (map.IsPassable(x, y))
{
WeightedGraphNode <double> connectionNode;
WeightedGraphNode <double> currentNode = new WeightedGraphNode <double>(Double.PositiveInfinity);
nodes[x, y] = currentNode;
currentNode.Position = new Vector2Int(x, y);
int prevX = x - 1;
int prevY = y - 1;
int nextY = y + 1;
if (prevX >= 0)
{
connectionNode = nodes[prevX, y];
ConnectNodes(currentNode, connectionNode, 1);
}
if (prevY >= 0)
{
connectionNode = nodes[x, prevY];
ConnectNodes(currentNode, connectionNode, 1);
}
if (prevX >= 0 && prevY >= 0 && neighbourMode == NeighbourMode.SidesAndDiagonals)
{
connectionNode = nodes[prevX, prevY];
ConnectNodes(currentNode, connectionNode, Sqrt2);
}
if (nextY < map.Height && prevX >= 0 && neighbourMode == NeighbourMode.SidesAndDiagonals)
{
connectionNode = nodes[prevX, nextY];
ConnectNodes(currentNode, connectionNode, Sqrt2);
}
}
else
{
nodes[x, y] = null;
}
}
}
WeightedGraph <double> weightedGraph = new WeightedGraph <double>(nodes, Double.PositiveInfinity);
return(weightedGraph);
;
}
private static void ConnectNodes(WeightedGraphNode <double> nodeA, WeightedGraphNode <double> nodeB,
double weight)
{
if (nodeA == null || nodeB == null)
{
return;
}
nodeA.SetWeight(nodeB, weight);
nodeB.SetWeight(nodeA, weight);
}
private static void MakeKruskals()
{
var A = new WeightedGraphNode <char>('A');
var B = new WeightedGraphNode <char>('B');
var C = new WeightedGraphNode <char>('C');
var D = new WeightedGraphNode <char>('D');
var E = new WeightedGraphNode <char>('E');
var F = new WeightedGraphNode <char>('F');
A.AddMutualNeighbor(B, 1);
A.AddMutualNeighbor(D, 2);
B.AddMutualNeighbor(D, 4);
B.AddMutualNeighbor(C, 2);
C.AddMutualNeighbor(D, 3);
C.AddMutualNeighbor(E, 4);
C.AddMutualNeighbor(F, 5);
E.AddMutualNeighbor(F, 1);
var G = new Graph <char>(A, B, C, D, E, F);
var MSF_G = G.KruskalsAlgorithmForMinimumSpanningForest();
var edges = MSF_G.GetEdgeList();
foreach (var edge in edges)
{
if (edge.Node1.GetValue().CompareTo(edge.Node2.GetValue()) > 0)
{
Console.WriteLine(edge.FlipDirection().ToString());
}
else
{
Console.WriteLine(edge.ToString());
}
}
}
/// <summary>
/// Runs an A* search to solve the board using manhattan distance as the heuristic function.
/// </summary>
/// <param name="initial_state"></param>
/// <param name="IsGreedy">Whether or not to use greedy best-first search instead of A*.</param>
/// <returns></returns>
public static NodePath <GameBoard> A_Star_Search(GameBoard initial_state, bool IsGreedy)
{
IPriorityQueue <WeightedNodePath <GameBoard> > priQueue = new Heap <WeightedNodePath <GameBoard> >(2000);
WeightedGraphNode <GameBoard> starting_path = new WeightedGraphNode <GameBoard>(initial_state);
var foundBoards = new HashSet <uint>();
var Start = new WeightedNodePath <GameBoard>(starting_path, null, 0);
priQueue.Enqueue(Start);
int totalProcessed = 0;
while (!priQueue.IsEmpty())
{
WeightedNodePath <GameBoard> cur = priQueue.Dequeue();
GameBoard top_gb = cur.Node.GetValue();
if (foundBoards.Contains(top_gb.GetHashValue()))
{
continue;
}
totalProcessed++;
if (top_gb.IsSolved)
{
Console.WriteLine("Solved Path Length of {0} with {1} boards revealed", cur.PathLength, totalProcessed);
return(cur);
}
//add to marked
foundBoards.Add(top_gb.GetHashValue());
int nextPathLength = cur.PathLength + 1;
//add all new nodes to the stack
foreach (var neighbor in top_gb.GetAllNeighborBoards())
{
if (foundBoards.Contains(neighbor.GetHashValue()))
{
continue;
}
double new_cost;
if (IsGreedy)
{
//cost ~= h(x)
new_cost = neighbor.GetSigmaManhattanDistance();
}
else
{
//cost = h(x) + g(x)
new_cost = neighbor.GetSigmaManhattanDistance() + nextPathLength;
}
var n_wgn = new WeightedGraphNode <GameBoard>(neighbor);
priQueue.Enqueue(new WeightedNodePath <GameBoard>(n_wgn, cur, new_cost, nextPathLength));
}
if (priQueue.IsEmpty())
{
Console.WriteLine("foobar!");
}
}
Console.WriteLine("foobar!");
return(null);
}
public void GetWeightedGraphTest()
{
int width = _rnd.Next(10, 20);
int height = _rnd.Next(10, 20);
NeighbourMode neighbourMode = NeighbourMode.SidesAndDiagonals;
MemoryCellFragment cellFragment = new MemoryCellFragment(width, height);
FillRandom(cellFragment);
WeightedGraph <double> weightedGraph = GraphGenerator.GetWeightedGraph(cellFragment, neighbourMode);
if (weightedGraph.Width != width)
{
Assert.Fail("Graph width is incorrect");
}
if (weightedGraph.Height != height)
{
Assert.Fail("Graph height is incorrect");
}
Vector2Int[] steps = Steps.GetSteps(neighbourMode);
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
WeightedGraphNode <double> node = (WeightedGraphNode <double>)weightedGraph[i, j];
bool cellPassable = cellFragment[i, j];
if (node == null)
{
if (cellPassable)
{
Assert.Fail($"Cell ({i}, {j}) is passable, but node does not exist");
}
continue;
}
int connectedCellsCount = 0;
foreach (var step in steps)
{
int xShift = i + step.X;
int yShift = j + step.Y;
bool stepInBounds = cellFragment.IsInBounds(xShift, yShift);
bool stepPassable = stepInBounds && cellFragment.IsPassable(xShift, yShift);
Debug.WriteLine($"Position: {node.Position}, Step: {step}, Neighbour: {node.Position + step}");
WeightedGraphNode <double> connection = (WeightedGraphNode <double>)GetConnection(node, step);
if (stepPassable)
{
connectedCellsCount++;
if (connection == null || double.IsInfinity(connection.GetWeight(node)))
{
Assert.Fail($"Node {node.Position} is not connected to position ({xShift}, {yShift}), that is passable");
}
}
else
{
if (connection != null && !double.IsInfinity(connection.GetWeight(node)))
{
Assert.Fail($"Node {node.Position} is connected to position ({xShift}, {yShift}), that is not passable");
}
}
}
if (node.Connections.Count != connectedCellsCount)
{
Assert.Fail("Number of connected nodes is incorrect");
}
}
}
}
static int heuristic(WeightedGraphNode <string> node)
{
var wcgn = (WeightedCoordinateGraphNode <string>)node;
return(Math.Abs(wcgn.X - 19) + Math.Abs(wcgn.Y - 45));
}