static string Run(string[] sudokuArray)
{
int row, column, index, number, maxNumberOfAttemptsToSolveSudoku = 1000, numberOfAttemptsToSolveSudoku = 0;
bool atLeastOneSimulation = false, stateHasBeenSaved = false, numbersAddedWithCertaintyAndThenNoCandidates = false;
SudokuBoard sudokuBoard = new SudokuBoard();
Candidates candidates = new Candidates();
int currentSudokuToSolve, numberOfSudokusToSolve = sudokuArray.Length;
string result = "S";
sudokuBoard.Init();
candidates.Init();
currentSudokuToSolve = 1;
while (currentSudokuToSolve <= numberOfSudokusToSolve && result == "S")
{
numberOfAttemptsToSolveSudoku = 0;
atLeastOneSimulation = false;
stateHasBeenSaved = false;
numbersAddedWithCertaintyAndThenNoCandidates = false;
sudokuBoard.SetWorkingSudokuBoard(currentSudokuToSolve - 1, sudokuArray);
candidates.SetCandidates(sudokuBoard);
while (numberOfAttemptsToSolveSudoku < maxNumberOfAttemptsToSolveSudoku && !sudokuBoard.SudokuSolved && !numbersAddedWithCertaintyAndThenNoCandidates)
{
if (numberOfAttemptsToSolveSudoku > 0)
{
sudokuBoard.RestoreState();
candidates.RestoreState();
}
while (candidates.HasCandidates)
{
number = 0;
sudokuBoard.ResetList();
while (number == 0 && sudokuBoard.NextCellInList())
{
number = candidates.TryFindNumberToSetInCellWithCertainty(sudokuBoard.CurrentRow, sudokuBoard.CurrentColumn);
}
if (number == 0)
{
candidates.SimulateOneNumber(sudokuBoard, out row, out column, out index, out number);
atLeastOneSimulation = true;
if (!stateHasBeenSaved)
{
sudokuBoard.SaveState();
candidates.SaveState();
stateHasBeenSaved = true;
}
}
else
{
row = sudokuBoard.CurrentRow;
column = sudokuBoard.CurrentColumn;
index = sudokuBoard.CurrentListIndex;
}
sudokuBoard.SetNumber(row, column, index, number);
candidates.UpdateCandidates(row, column, number);
}
if (!sudokuBoard.SudokuSolved)
{
if (!atLeastOneSimulation)
{
numbersAddedWithCertaintyAndThenNoCandidates = true;
}
else
{
sudokuBoard.CheckIfCanUpdateBestSoFarSudokuBoard();
numberOfAttemptsToSolveSudoku++;
}
}
}
result = ProcessResult(sudokuBoard, currentSudokuToSolve - 1, sudokuArray);
if ((currentSudokuToSolve % 500) == 0)
{
Console.Write("\r" + currentSudokuToSolve.ToString());
}
currentSudokuToSolve++;
}
return(result);
}
static void Main(string[] args)
{
int row, column, index, number, maxNumberOfAttemptsToSolveSudoku = 100, numberOfAttemptsToSolveSudoku = 0;
bool atLeastOneSimulation = false, stateHasBeenSaved = false, numbersAddedWithCertaintyAndThenNoCandidates = false;
SudokuBoard sudokuBoard = new SudokuBoard();
Candidates candidates = new Candidates();
string msg = sudokuBoard.Init(args);
if (msg != null)
{
PrintResult(false, msg);
return;
}
msg = sudokuBoard.Validate();
if (msg != null)
{
PrintResult(false, msg);
return;
}
if (sudokuBoard.CellsRemainToSet == 0)
{
PrintResult(false, "A complete sudoku was given as input. There is nothing to solve.");
return;
}
candidates.Init(sudokuBoard);
if (!candidates.HasCandidates)
{
PrintResult(false, "It is not possible to add any number to the sudoku.");
return;
}
while (numberOfAttemptsToSolveSudoku < maxNumberOfAttemptsToSolveSudoku && !sudokuBoard.SudokuSolved && !numbersAddedWithCertaintyAndThenNoCandidates)
{
if (numberOfAttemptsToSolveSudoku > 0)
{
sudokuBoard.RestoreState();
candidates.RestoreState();
}
while (candidates.HasCandidates)
{
number = 0;
sudokuBoard.ResetList();
while (number == 0 && sudokuBoard.NextCellInList())
{
number = candidates.TryFindNumberToSetInCellWithCertainty(sudokuBoard.CurrentRow, sudokuBoard.CurrentColumn);
}
if (number == 0)
{
candidates.SimulateOneNumber(sudokuBoard, out row, out column, out index, out number);
atLeastOneSimulation = true;
if (!stateHasBeenSaved)
{
sudokuBoard.SaveState();
candidates.SaveState();
stateHasBeenSaved = true;
}
}
else
{
row = sudokuBoard.CurrentRow;
column = sudokuBoard.CurrentColumn;
index = sudokuBoard.CurrentListIndex;
}
sudokuBoard.SetNumber(row, column, index, number);
candidates.UpdateCandidates(row, column, number);
}
if (!sudokuBoard.SudokuSolved)
{
if (!atLeastOneSimulation)
{
numbersAddedWithCertaintyAndThenNoCandidates = true;
}
else
{
sudokuBoard.CheckIfCanUpdateBestSoFarSudokuBoard();
numberOfAttemptsToSolveSudoku++;
}
}
}
PrintResult(true, null, args, sudokuBoard);
}
private static void PrintResult(bool initialSudokuBoardHasCandidates, string msg, string[] args = null, SudokuBoard sudokuBoard = null)
{
if (initialSudokuBoardHasCandidates)
{
if (sudokuBoard.SudokuSolved)
{
msg = string.Format("The sudoku was solved. {0} number(s) added to the original {1}.", 81 - sudokuBoard.NumberOfCellsSetInInputSudokuBoard, sudokuBoard.NumberOfCellsSetInInputSudokuBoard);
}
else
{
msg = string.Format("The sudoku was partially solved. {0} number(s) added to the original {1}. Unable to set {2} number(s).", sudokuBoard.NumberOfCellsSetInBestSoFar - sudokuBoard.NumberOfCellsSetInInputSudokuBoard, sudokuBoard.NumberOfCellsSetInInputSudokuBoard, 81 - sudokuBoard.NumberOfCellsSetInBestSoFar);
}
PrintSudokuBoard(args, msg, sudokuBoard);
}
Console.Write(msg);
}
static void Main(string[] args)
{
int row, column, index, number, maxNumberOfAttemptsToSolveSudoku = 100, numberOfAttemptsToSolveSudoku = 0;
bool atLeastOneSimulation = false, stateHasBeenSaved = false, numbersAddedWithCertaintyAndThenNoCandidates = false;
SudokuBoard sudokuBoard = new SudokuBoard();
Candidates candidates = new Candidates();
ArrayList debugTotalCellsAdded = new ArrayList();
string debugDirectory, debugString, debugFileNameFullPath;
string[] debugCategory = new string[1];
string[] debugInfo = new string[1];
int debugTry, debugAddNumber, debugSquare;
int[][][] squareCellToRowColumnMapper;
squareCellToRowColumnMapper = ReturnSquareCellToRowColumnMapper();
string msg = sudokuBoard.Init(args);
if (msg != null)
{
PrintResult(false, msg);
return;
}
msg = sudokuBoard.Validate();
if (msg != null)
{
PrintResult(false, msg);
return;
}
if (sudokuBoard.CellsRemainToSet == 0)
{
PrintResult(false, "A complete sudoku was given as input. There is nothing to solve.");
return;
}
candidates.Init(sudokuBoard);
if (!candidates.HasCandidates)
{
PrintResult(false, "It is not possible to add any number to the sudoku.");
return;
}
debugDirectory = DebugCreateAndReturnDebugDirectory();
debugTry = 0;
while (numberOfAttemptsToSolveSudoku < maxNumberOfAttemptsToSolveSudoku && !sudokuBoard.SudokuSolved && !numbersAddedWithCertaintyAndThenNoCandidates)
{
debugTry += 1;
debugAddNumber = 0;
debugTotalCellsAdded.Clear();
if (numberOfAttemptsToSolveSudoku > 0)
{
sudokuBoard.RestoreState();
candidates.RestoreState();
}
while (candidates.HasCandidates)
{
number = 0;
sudokuBoard.ResetList();
while (number == 0 && sudokuBoard.NextCellInList())
{
number = candidates.TryFindNumberToSetInCellWithCertainty(sudokuBoard.CurrentRow, sudokuBoard.CurrentColumn, debugCategory);
}
if (number == 0)
{
candidates.SimulateOneNumber(sudokuBoard, debugInfo, out row, out column, out index, out number);
atLeastOneSimulation = true;
if (!stateHasBeenSaved)
{
sudokuBoard.SaveState();
candidates.SaveState();
stateHasBeenSaved = true;
}
debugCategory[0] = "Simulated";
}
else
{
row = sudokuBoard.CurrentRow;
column = sudokuBoard.CurrentColumn;
index = sudokuBoard.CurrentListIndex;
}
debugTotalCellsAdded.Add(new int[] { row, column });
debugSquare = 1 + (3 * ((row - 1) / 3)) + ((column - 1) / 3);
debugString = "(row, column, square, number, category) = (" + row.ToString() + ", " + column.ToString() + ", " + debugSquare.ToString() + ", " + number.ToString() + ", " + debugCategory[0] + ")\r\n\r\n";
debugString += "Total cells added (" + debugTotalCellsAdded.Count.ToString() + " cells): " + DebugReturnCells(debugTotalCellsAdded) + "\r\n\r\n";
if (debugCategory[0] == "Simulated")
{
debugString += debugInfo[0] + "\r\n\r\n";
}
debugString += "Data before update:\r\n\r\n" + DebugReturnInfo(sudokuBoard._workingSudokuBoard, sudokuBoard._cellsRemainToSet, ReturnNumberOfCandidates(candidates._candidates, true, numberOfAttemptsToSolveSudoku, debugAddNumber), candidates._candidates, squareCellToRowColumnMapper);
sudokuBoard.SetNumber(row, column, index, number);
candidates.UpdateCandidates(row, column, number);
debugString += "\r\nData after update:\r\n\r\n" + DebugReturnInfo(sudokuBoard._workingSudokuBoard, sudokuBoard._cellsRemainToSet, ReturnNumberOfCandidates(candidates._candidates, false, numberOfAttemptsToSolveSudoku, debugAddNumber), candidates._candidates, squareCellToRowColumnMapper);
debugAddNumber += 1;
debugFileNameFullPath = debugDirectory + "\\" + DebugReturnFileName(debugTry, debugAddNumber);
File.WriteAllText(debugFileNameFullPath, debugString);
}
if (!sudokuBoard.SudokuSolved)
{
if (!atLeastOneSimulation)
{
numbersAddedWithCertaintyAndThenNoCandidates = true;
}
else
{
sudokuBoard.CheckIfCanUpdateBestSoFarSudokuBoard();
numberOfAttemptsToSolveSudoku++;
}
}
}
PrintResult(true, null, args, sudokuBoard);
}