private static void PrintGrid(SudokuGrid grid)
{
for (int i = 0; i < grid.Rows; i++)
{
for (int j = 0; j < grid.Columns; j++)
{
Node thisNode = grid.GetNode(i, j);
if (j == 5) // last column, go onto a newline
{
Console.WriteLine(thisNode.Value);
if (i == 1 || i == 3) // 2nd or 4th row, write an extra newline so we can visualize the 2x3 boxes
{
Console.WriteLine();
}
}
else
{
Console.Write(thisNode.Value);
}
if (j == 2) // space after 3rd column to help us visualize the 2x3 boxes
{
Console.Write(" ");
}
}
}
}
private Queue <Arc> GetAllArcs()
{
Queue <Arc> arcs = new Queue <Arc>();
foreach (Node node1 in _grid.Grid)
{
foreach (Node node2 in _grid.Grid)
{
if (node1 != node2 && // it's the same node
SudokuGrid.NodesAreRelated(node1, node2) && // nodes have to be related to be considered an arc
(node1.Editable || node2.Editable)) // at least one of them should be editable, otherwise why bother?
{
Arc arc = new Arc()
{
Node1 = node1,
Node2 = node2
};
if (!arcs.Contains(arc))
{
arcs.Enqueue(arc);
}
}
}
}
return(arcs);
}
protected CSPSolution CompleteSolve(string name, SudokuGrid grid, TimeSpan elapsed, int processed, int iterations)
{
CSPSolution solution = new CSPSolution();
solution.AlgorithmName = name;
solution.SolutionGrid = grid;
solution.TimeElapsed = elapsed;
solution.Processed = processed;
solution.Iterations = iterations;
return(solution);
}
// How many constraints are being violated by the current guess?
private int PerformEvaluationFunction()
{
int violations = 0;
foreach (Node node in _solvedGrid.Grid)
{
// The valid values for this node
List <int> validValues = SudokuGrid.GetNodeDomain(node);
// If the current value is not one of the valid ones, we have a violation
if (!validValues.Contains(node.Value))
{
violations++;
}
}
return(violations);
}
public BacktrackingSolver(SudokuGrid initialGrid)
: base(initialGrid)
{
// Use default constructor
}
public ArcConsistencySolver(SudokuGrid initialGrid) : base(initialGrid)
{
// Use default constructor
}
private static SudokuGrid LoadGridFromFile(string filePath)
{
SudokuGrid grid = new SudokuGrid(6, 6, File.ReadAllText(filePath));
return(grid);
}
static void Main(string[] args)
{
Console.WriteLine($"{args[0]} loaded");
bool quit = false;
while (!quit)
{
SudokuGrid initialProblem = LoadGridFromFile(args[0]);
Console.WriteLine();
Console.WriteLine("Choose an algorithm: ArcConsistency (ac), BacktrackingSearch (bts), or GradientDescent (gd)");
Console.WriteLine("Press Q to quit, or P to print the initial grid");
string choice = Console.ReadLine();
List <CSPSolver> problemSolvers = new List <CSPSolver>();
switch (choice.ToLower().Trim())
{
case "print":
case "p":
PrintGrid(initialProblem);
break;
case "q":
case "quit":
quit = true;
break;
case "ac":
case "arcconsistency":
case "arc":
problemSolvers.Add(new ArcConsistencySolver(initialProblem));
break;
case "backtracking":
case "bts":
case "bt":
case "backtrackingsearch":
problemSolvers.Add(new BacktrackingSolver(initialProblem));
break;
case "gradientdescent":
case "gd":
case "gradient":
problemSolvers.Add(new GradientDescentSolver(initialProblem));
break;
default: // just do the solution for all of them
problemSolvers.Add(new ArcConsistencySolver(initialProblem));
problemSolvers.Add(new BacktrackingSolver(initialProblem));
problemSolvers.Add(new GradientDescentSolver(initialProblem));
break;
}
foreach (CSPSolver solver in problemSolvers)
{
CSPSolution solution = solver.Solve();
PrintSolution(solution);
}
}
}
// Default constructor for all solvers. They all use a SudokuGrid
protected CSPSolver(SudokuGrid initialGrid)
{
_grid = initialGrid;
}
public GradientDescentSolver(SudokuGrid initialGrid)
: base(initialGrid)
{
_solvedGrid = initialGrid; // start with the initial grid
_solvedGrid.Randomize();
}