private static Sudoku Solve(Sudoku sudoku, ref int functionCallCount)
{
functionCallCount++;
var(row, column) = SudokuInspector.FindFirstEmptyPosition(sudoku);
if (row == -1)
{
return(sudoku);
}
for (var number = 1; number <= sudoku.FieldDimension; number++)
{
if (!sudoku.IsNumberValid(row, column, number))
{
continue;
}
sudoku.SetCell(row, column, number);
var solution = Solve(sudoku, ref functionCallCount);
if (solution != null)
{
return(solution);
}
sudoku.ResetCell(row, column);
}
return(null);
}
private static void SolveSudokuAndDisplayResults(string sudokuPath)
{
PrintHeader(sudokuPath);
Sudoku initial;
try
{
initial = SudokuParser.Parse(sudokuPath);
}
catch (Exception e)
{
Console.WriteLine();
Console.WriteLine($"Error: {e.Message}");
Console.WriteLine();
return;
}
var maxDepth = SudokuInspector.CountEmptyCells(initial);
PrintSudoku(initial);
Console.WriteLine($"Solving puzzle '{sudokuPath}'...");
var(solution, functionCallCount, elapsedTimeInMs) = SudokuSolver.Solve(initial);
if (solution != null)
{
Console.WriteLine("Done! Solution:");
PrintSudoku(solution);
Console.WriteLine($"Puzzle '{sudokuPath}' solved in {elapsedTimeInMs:F3}ms.");
Console.WriteLine($"Solution found at depth {maxDepth}, in {functionCallCount} function calls.");
Console.WriteLine($"Validity check: {(SudokuValidator.Validate(solution) ? "Passed!" : "Failed.")}");
}
else
{
Console.WriteLine("Puzzle could not be solved. Please make sure the puzzle was defined properly.");
}
Console.WriteLine();
}
