completed puzzleState: implementation of StateBase for FifteenPuzzle

FifteenPuzzle/FifteenPuzzle.csproj

@@ -51,6 +51,12 @@
   <ItemGroup>
     <None Include="App.config" />
   </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Search\Search.csproj">
+      <Project>{B081B079-214A-4C6B-842B-83663FD8CEA9}</Project>
+      <Name>Search</Name>
+    </ProjectReference>
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

FifteenPuzzle/Program.cs

@@ -1,15 +1,17 @@
 using System;
 
 namespace FifteenPuzzle
-{	public class Program
+{	
+	public class Program
 	{
 		public static void Main(string[] args)
 		{
 			try {
 				if(args.Length == 0)
 				{
 					RunAllTestCases();
-				} else if (args.Length == 2)
+				} 
+				else if (args.Length == 2)
 				{
 					RunSingleSearch();
 				}

FifteenPuzzle/PuzzleState.cs

@@ -1,12 +1,228 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using Search;
 
 namespace FifteenPuzzle
 {
-	class PuzzleState
+	public struct PuzzleSpace
 	{
+		public int Row { get; private set; }
+		public int Col { get; private set; }
+
+		public PuzzleSpace(int row, int col)
+		{
+			Row = row;
+			Col = col;
+		}
+	}
+
+	public class PuzzleState : StateBase
+	{
+		private Dictionary<int, PuzzleSpace> _valueLookup;
+
+		public int[,] Board { get; private set; }
+
+		public PuzzleState(int[,] board, Dictionary<int, PuzzleSpace> valueLookup)
+		{
+			Board = board;
+			_valueLookup = valueLookup;
+		}
+
+		public PuzzleState(string stateAsString)
+		{
+			// example stateAsString:
+			// ((1 5 3 7) (4 9 2 11) (8 13 10 14) (12 15 0 6) (3 2))
+
+			Board = new int[4,4];
+			string[] parts = stateAsString.Split(new[] { ") (" }, StringSplitOptions.None);
+
+			for (int i = 0; i < 4; i++)
+			{
+				string part = parts[i].TrimStart(new[] { '(', ' ' }).TrimEnd(new[] { ')', ' ' });
+				string[] nums = part.Split();
+
+				for (int j = 0; j < 4; j++)
+				{
+					int num = int.Parse(nums[j]);
+					Board[i, j] = num;
+					_valueLookup[num] = new PuzzleSpace(i, j);
+
+				}
+			}
+		}
+
+		#region equality
+
+		public override bool Equals(object obj)
+		{
+			if (ReferenceEquals(obj, null)) return false;
+			if (ReferenceEquals(this, obj)) return true;
+			if (obj.GetType() != GetType()) return false;
+			return Equals(obj as PuzzleState);
+		}
+
+		public override bool Equals(StateBase other)
+		{
+			return this.GetHashCode().Equals(other.GetHashCode());
+		}
+
+		#endregion
+
+		public override int GetHashCode()
+		{
+			int hashCode = 13;
+
+			for (int i = 0; i < 4;  i++)
+			{
+				for (int j = 0; j < 4; j++)
+				{
+					hashCode = (hashCode * 397) ^ Board[i, j] ^ (i + j);
+				}	
+			}
+
+			return hashCode;
+		}
+
+		public PuzzleSpace GetSpace(int num)
+		{
+			return _valueLookup[num];
+		}
+
+		public PuzzleState Clone()
+		{
+			Dictionary<int, PuzzleSpace> valueLookup = new Dictionary<int, PuzzleSpace>(16);
+			int[,] newBoard = new int[4, 4];
+			for (int i = 0; i < 4; i++)
+			{
+				for (int j = 0; j < 4; j++)
+				{
+					int num = Board[i, j];
+					newBoard[i, j] = num;
+					valueLookup[num] = new PuzzleSpace(i, j);
+				}
+			}
+
+			return new PuzzleState(newBoard, valueLookup);
+		}
+
+		#region Actions
+
+		public PuzzleState Up()
+		{
+
+			PuzzleSpace oldVoidLocation = GetSpace(0);
+
+			if (oldVoidLocation.Row == 0)
+			{
+				return null;
+			}
+
+			PuzzleState newState = Clone();
+			PuzzleSpace newVoidLocation = new PuzzleSpace(oldVoidLocation.Row - 1, oldVoidLocation.Col);
+
+			int valToBeSwapped = newState.Board[newVoidLocation.Row, newVoidLocation.Col];
+			newState.Board[newVoidLocation.Row, newVoidLocation.Col] = 0;
+			newState.Board[oldVoidLocation.Row, oldVoidLocation.Col] = valToBeSwapped;
+			newState._valueLookup[0] = newVoidLocation;
+			newState._valueLookup[valToBeSwapped] = oldVoidLocation;
+			return newState;
+		}
+
+		public PuzzleState Down()
+		{
+			PuzzleSpace oldVoidLocation = GetSpace(0);
+
+			if (oldVoidLocation.Row == 3)
+			{
+				return null;
+			}
+
+			PuzzleState newState = Clone();
+			PuzzleSpace newVoidLocation = new PuzzleSpace(oldVoidLocation.Row + 1, oldVoidLocation.Col);
+
+			int valToBeSwapped = newState.Board[newVoidLocation.Row, newVoidLocation.Col];
+			newState.Board[newVoidLocation.Row, newVoidLocation.Col] = 0;
+			newState.Board[oldVoidLocation.Row, oldVoidLocation.Col] = valToBeSwapped;
+			newState._valueLookup[0] = newVoidLocation;
+			newState._valueLookup[valToBeSwapped] = oldVoidLocation;
+			return newState;
+
+		}
+
+		public PuzzleState Left()
+		{
+			PuzzleSpace oldVoidLocation = GetSpace(0);
+
+			if (oldVoidLocation.Col == 0)
+			{
+				return null;
+			}
+
+			PuzzleState newState = Clone();
+
+			PuzzleSpace newVoidLocation = new PuzzleSpace(oldVoidLocation.Row, oldVoidLocation.Col - 1);
+
+			int valToBeSwapped = newState.Board[newVoidLocation.Row, newVoidLocation.Col];
+			newState.Board[newVoidLocation.Row, newVoidLocation.Col] = 0;
+			newState.Board[oldVoidLocation.Row, oldVoidLocation.Col] = valToBeSwapped;
+			newState._valueLookup[0] = newVoidLocation;
+			newState._valueLookup[valToBeSwapped] = oldVoidLocation;
+			return newState;
+
+		}
+
+		public PuzzleState Right()
+		{
+			PuzzleSpace oldVoidLocation = GetSpace(0);
+
+			if (oldVoidLocation.Col == 3)
+			{
+				return null;
+			}
+
+			PuzzleState newState = Clone();
+			PuzzleSpace newVoidLocation = new PuzzleSpace(oldVoidLocation.Row, oldVoidLocation.Col + 1);
+
+			int valToBeSwapped = newState.Board[newVoidLocation.Row, newVoidLocation.Col];
+			newState.Board[newVoidLocation.Row, newVoidLocation.Col] = 0;
+			newState.Board[oldVoidLocation.Row, oldVoidLocation.Col] = valToBeSwapped;
+			newState._valueLookup[0] = newVoidLocation;
+			newState._valueLookup[valToBeSwapped] = oldVoidLocation;
+			return newState;
+
+		}
+
+		#endregion
+
+		public override IDictionary<string, StateBase> Successors()
+		{
+			Dictionary<string, StateBase> dict = new Dictionary<string, StateBase>();
+			var u = Up();
+			var d = Down();
+			var l = Left();
+			var r = Right();
+
+			if (u != null)
+			{
+				dict["U"] = u;
+			}
+
+			if (d != null)
+			{
+				dict["D"] = d;
+			}
+
+			if (l != null)
+			{
+				dict["L"] = l;
+			}
+
+			if (r != null)
+			{
+				dict["R"] = r;
+			}
+
+			return dict;
+		}
 	}
 }