static void Main(string[] args)
{
Console.WriteLine("==== Console program for knights travails problem =====\n\n");
Console.WriteLine("Please enter source and destination(algebraic notation) \nseparated by space(i.e a8 b7):\n");
string inp = Console.ReadLine();
while (!String.IsNullOrEmpty(inp) && !inp.ToLowerInvariant().Equals("q") )
{
string[] inpSquares = inp.Split(' ');
string src = inpSquares[0].Trim().ToLowerInvariant();
string dest = inpSquares[1].Trim().ToLowerInvariant();
var board = new ChessBoard();
var knightGraph = new KnightGraph(board);
var shortestPathStrategy = new DijkstraAlgorithm(graph: knightGraph, source: board.Squares[src]);
var shortestPath = shortestPathStrategy.GetShortestPathTo(board.Squares[dest]);
Console.WriteLine(String.Format("Shortest Path from {0} to {1} : ", src, dest));
if(shortestPath==null)
Console.WriteLine("unreachable");
else
shortestPath.ForEach(sq=>Console.Write(sq+" "));
Console.Write("\nWant to continue?(y/n)");
string cont = Console.ReadLine();
if(!cont.ToLowerInvariant().Equals("y"))
break;
Console.WriteLine("\nEnter source and destination separated by space");
inp = Console.ReadLine();
}
Console.WriteLine();
}
public void KnightGraph()
{
var board = new ChessBoard();
var knightGraph = new KnightGraph(board);
Assert.AreEqual(2, knightGraph.EdgesAdjacencyList[board.Squares["a1"]].Count);
Assert.AreEqual(8, knightGraph.EdgesAdjacencyList[board.Squares["c3"]].Count);
Assert.AreEqual(3, knightGraph.EdgesAdjacencyList[board.Squares["a2"]].Count);
Assert.AreEqual(4, knightGraph.EdgesAdjacencyList[board.Squares["b2"]].Count);
Assert.AreEqual(6, knightGraph.EdgesAdjacencyList[board.Squares["c2"]].Count);
}
public void GetShortestPathToTest()
{
var board = new ChessBoard();
var knightGraph = new KnightGraph(board);
var pathStrategy = new DijkstraAlgorithm(board.Squares["b7"], knightGraph);
var path = pathStrategy.GetShortestPathTo(board.Squares["a8"]);
foreach (var square in path)
{
Console.WriteLine(square);
}
}
public void ChessBoard()
{
var board = new ChessBoard();
foreach (var sq in board.Squares)
{
Console.WriteLine(sq.ToString() + String.Format(" r: {0}, c: {1}", sq.Value.RowPosition, sq.Value.ColPosition));
}
Assert.AreEqual("a1", board.Squares["a1"].ToString());
Assert.AreEqual("a2", board.Squares["a2"].ToString());
var square = board.GetSquare(5, 6);
Assert.AreEqual(5, square.RowPosition);
Assert.AreEqual(6, square.ColPosition);
Assert.IsNull(board.GetSquare(0, 8));
Assert.IsNotNull(board.GetSquare(8, 8));
Assert.IsNotNull(board.GetSquare(1, 1));
}
public KnightGraph(ChessBoard board)
: base(board)
{
AdjacencyList=new Dictionary<Square, List<Square>>();
//initialize graph edges for knights moves
foreach (var sq in Board.Squares)
{
var sqList = new List<Square>();
var square = sq.Value;
//add edges to eight possible moves for the knight
var moveSq = Board.GetSquare(square.RowPosition + 2, square.ColPosition + 1);
if(moveSq!=null) sqList.Add(moveSq);
moveSq = Board.GetSquare(square.RowPosition + 2, square.ColPosition - 1);
if (moveSq != null) sqList.Add(moveSq);
moveSq = Board.GetSquare(square.RowPosition - 2, square.ColPosition + 1);
if (moveSq != null) sqList.Add(moveSq);
moveSq = Board.GetSquare(square.RowPosition - 2, square.ColPosition - 1);
if (moveSq != null) sqList.Add(moveSq);
moveSq = Board.GetSquare(square.RowPosition + 1, square.ColPosition + 2);
if (moveSq != null) sqList.Add(moveSq);
moveSq = Board.GetSquare(square.RowPosition + 1, square.ColPosition - 2);
if (moveSq != null) sqList.Add(moveSq);
moveSq = Board.GetSquare(square.RowPosition - 1, square.ColPosition + 2);
if (moveSq != null) sqList.Add(moveSq);
moveSq = Board.GetSquare(square.RowPosition - 1, square.ColPosition - 2);
if (moveSq != null) sqList.Add(moveSq);
//add the entry to adjacency list
AdjacencyList.Add(square, sqList);
}
}
protected ChessBoardPieceGraph(ChessBoard board)
{
Board = board;
}