public void NoSolutionFoundToUnsolvableBoard()
{
int[,] board = GetUnsolvableBoard();
Solver solver = new Solver();
bool solved = solver.Solve(board);
Assert.IsFalse(solved);
}
public void SolutionIsValid()
{
int[,] board = GetBoard();
Solver solver = new Solver();
solver.Solve(board);
TestHelper.TestSolutionValid(solver.GetFirstSolution());
}
public void CanSolveSampleBoard()
{
int[,] board = GetBoard();
Solver solver = new Solver();
bool solved = solver.Solve(board);
Assert.IsTrue(solved);
}
public void CanSolveEmptyBoard()
{
Solver solver = new Solver();
int[,] board = new int[9, 9];
bool solved = solver.Solve(board);
// there are solutions to an empty board
Assert.IsTrue(solved);
}
public void EmptyBoardSolutionIsValid()
{
int[,] board = new int[9, 9];
Solver solver = new Solver();
solver.Solve(board);
int[,] firstSolution = solver.GetFirstSolution();
TestHelper.TestSolutionValid(firstSolution);
}
public void CanSolveSimpleBoard()
{
Solver solver = new Solver();
int[,] board = GetSimpleBoardToSolve();
bool solved = solver.Solve(board);
// there is a solution to this board
Assert.IsTrue(solved);
Assert.GreaterOrEqual(solver.SolutionCount, 1);
}
public void CanSolveBoard()
{
Solver solver = new Solver();
int[,] board = GetBoard();
bool solved = solver.Solve(board);
// there is a solution to this board
Assert.IsTrue(solved);
Assert.AreEqual(1, solver.SolutionCount);
}
public void SolutionIsCorrect()
{
Solver solver = new Solver();
int[,] board = GetBoard();
solver.Solve(board);
int[,] solution = solver.GetFirstSolution();
TestHelper.TestSolutionValid(solution);
TestHelper.BoardsAreSameInFilledCells(solution, GetBoardSolution());
}
public void TimeSolution()
{
Solver solver = new Solver();
int[,] board = GetBoard();
Stopwatch timer = new Stopwatch();
timer.Start();
solver.Solve(board);
timer.Stop();
TimeSpan timeToSolve = timer.Elapsed;
Assert.Fail("Solving took " + timeToSolve);
}
public string generateString(int holeNumber)
// generate n boards...
{
int NUM_MAX = gridSize * 3 - 6; // number of random generated numbers
status = 0;
List <int> selected = new List <int>();
Random r = new Random();
bool solved = false;
//lasvegas algorithms.
do // while bm has a solution
{
sv = null;
do // while newBoard got valid puzzle
{
int numberSelect = NUM_MAX;
selected.Clear();
newBoard = initBoard.Copy();
while (numberSelect > 0)
{
int inputPosition = r.Next(1, gridSize * gridSize);
if (!selected.Contains(inputPosition))
{
selected.Add(inputPosition);
newBoard.setBoard(inputPosition / gridSize, inputPosition % gridSize, r.Next(1, gridSize));
numberSelect--;
}
}
}while (!newBoard.isValid());
sv = new Solver(newBoard);
sv.PresentBoard += PresentBoard;
bool DONE = false;
var t0 = new System.Threading.Thread(() => {
threeseconds();
if (DONE == false)
{
sv.killSolver();
DONE = true;
}
});
var t1 = new System.Threading.Thread(() =>
{
solved = sv.solve(2, true);
Console.WriteLine("solved in three seconds...");
DONE = true;
});
t0.Start();
t1.Start();
while (!DONE)
{
System.Threading.Thread.Sleep(200);
}
t0.Abort();
t1.Abort();
}while (!solved);
Console.WriteLine("digging hole initiated");
status = 1; // DO NOT PRESENT WHILE THIS REGION
Board Digged = sv.solution.Copy();
bool[,] DONOTDIG = new bool[gridSize, gridSize];
//holeNumber = r.Next(54, 73); // 9x9 Normal difficulty (temporal), we should implement difficulty later
sv = null;
int[] shuffledArr = new int[gridSize * gridSize];
for (int i = 0; i < gridSize * gridSize; i++)
{
DONOTDIG[i / gridSize, i % gridSize] = false;
shuffledArr[i] = i;
}
// shuffling size array...
int n = shuffledArr.Length;
while (n > 1)
{
int k = r.Next(n--);
int temp = shuffledArr[n];
shuffledArr[n] = shuffledArr[k];
shuffledArr[k] = temp;
}
//lets dig holes!
int cnt = gridSize * gridSize - 1;
while (holeNumber > 0)
{
if (cnt == 0)
{
break;
}
int digRow = shuffledArr[cnt] / gridSize;
int digCol = shuffledArr[cnt--] % gridSize;
int diggedNumber = Digged.getBoard(digRow, digCol);
if (DONOTDIG[digRow, digCol])
{
continue;
}
bool nope = false;
holeNumber--;
for (int i = 1; i <= gridSize; i++)
{
if (i == diggedNumber)
{
continue;
}
Digged.setBoard(digRow, digCol, i);
sv = new Solver(Digged);
if (sv.solve(2, true))
{
DONOTDIG[digRow, digCol] = true;
Digged.setBoard(digRow, digCol, diggedNumber);
nope = true;
holeNumber++;
break;
}
}
if (!nope)
{
DONOTDIG[digRow, digCol] = true;
//Console.WriteLine("digging #{0}: {1}, {2}", holeNumber, digRow, digCol);
Digged.setBoard(digRow, digCol, 0);
newBoard = Digged.Copy();
}
}
SolBoard = Digged.Copy();
Console.WriteLine("generating complete");
Console.WriteLine(Digged.ToString());
PresentBoard(this, new PresentBoardArgs(Digged.ToString()));
return(Digged.ToString());
}
public static void Hint(Board board)
{
var solver = new Solver(board);
solver.Hint();
}
private void RemoveRandomIntegers(int[,] sudokuArray)
{
var r = new Random();
var boolArray = new bool[5] {
false, false, false, false, false
};
var excludedCoordinatesList = new List <int[]>();
switch (difficulty)
{
case Difficulty.Easy:
break;
case Difficulty.Normal:
boolArray[0] = true;
break;
case Difficulty.Hard:
boolArray[0] = true;
boolArray[1] = true;
break;
case Difficulty.VeryHard:
boolArray[0] = true;
boolArray[1] = true;
boolArray[2] = true;
boolArray[3] = true;
break;
case Difficulty.ExtremelyHard:
boolArray[0] = true;
boolArray[1] = true;
boolArray[2] = true;
boolArray[3] = true;
boolArray[4] = true;
break;
}
for (int j = 0; j < 5; j++)
{
var rowsList = RandomizeList(integersList);
for (int i = 0; i < rowsList.Count; i++)
{
var coordinate = new int[2] {
r.Next(0, fieldsPerRowAmount), rowsList[i] - 1
};
int n = sudokuArray[coordinate[0], coordinate[1]];
if (n != 0 && !Solver.CheckIfCoordinateListContainsCoordinate(excludedCoordinatesList, coordinate))
{
sudokuArray[coordinate[0], coordinate[1]] = 0;
if (CheckIfDifficultyMet(difficulty, sudokuArray) == -1)
{
sudokuArray[coordinate[0], coordinate[1]] = n;
excludedCoordinatesList.Add(coordinate);
}
else
{
var p = Solver.RateSudokuGrid(this, Solver.CopySudoku(sudokuArray), boolArray[0], boolArray[1], boolArray[2], boolArray[3], boolArray[4]);
if (p == 0 || p > difficultyRange[1])
{
sudokuArray[coordinate[0], coordinate[1]] = n;
excludedCoordinatesList.Add(coordinate);
}
}
}
}
var columnList = RandomizeList(rowsList);
for (int i = 0; i < columnList.Count; i++)
{
var coordinate = new int[2] {
columnList[i] - 1, r.Next(0, fieldsPerRowAmount)
};
int n = sudokuArray[coordinate[0], coordinate[1]];
if (n != 0 && !Solver.CheckIfCoordinateListContainsCoordinate(excludedCoordinatesList, coordinate))
{
sudokuArray[coordinate[0], coordinate[1]] = 0;
if (CheckIfDifficultyMet(difficulty, sudokuArray) == -1)
{
sudokuArray[coordinate[0], coordinate[1]] = n;
excludedCoordinatesList.Add(coordinate);
}
else
{
var p = Solver.RateSudokuGrid(this, Solver.CopySudoku(sudokuArray), boolArray[0], boolArray[1], boolArray[2], boolArray[3], boolArray[4]);
if (p == 0 || p > difficultyRange[1])
{
sudokuArray[coordinate[0], coordinate[1]] = n;
excludedCoordinatesList.Add(coordinate);
}
}
}
}
}
var rowList = RandomizeList(integersList);
for (int x = 0; x < fieldsPerRowAmount; x++)
{
int row = rowList[x] - 1;
var columnList = RandomizeList(rowList);
for (int y = 0; y < fieldsPerRowAmount; y++)
{
int col = columnList[x] - 1;
var coordinate = new int[2] {
col, row
};
int n = sudokuArray[col, row];
if (n != 0 && !Solver.CheckIfCoordinateListContainsCoordinate(excludedCoordinatesList, coordinate))
{
sudokuArray[col, row] = 0;
if (CheckIfDifficultyMet(difficulty, sudokuArray) == -1)
{
sudokuArray[coordinate[0], coordinate[1]] = n;
excludedCoordinatesList.Add(coordinate);
}
else
{
var p = Solver.RateSudokuGrid(this, Solver.CopySudoku(sudokuArray), boolArray[0], boolArray[1], boolArray[2], boolArray[3], boolArray[4]);
if (p == 0 || p > difficultyRange[1])
{
sudokuArray[coordinate[0], coordinate[1]] = n;
excludedCoordinatesList.Add(coordinate);
}
else
{
Console.WriteLine(p);
}
}
}
}
}
}
private void CreateIncompleteSudokuGrid()
{
int[,] sudokuArray = Solver.CopySudoku(SudokuCompleteArray);;
protectedPatternsList = DetermineProtectedPatterns();
if (boxPerRowAmount == 3)
{
switch (difficulty)
{
case Difficulty.Easy:
difficultyRange[0] = 450;
difficultyRange[1] = 530;
break;
case Difficulty.Normal:
if (diagonalRows)
{
difficultyRange[0] = 560;
difficultyRange[1] = 660;
}
else
{
difficultyRange[0] = 530;
difficultyRange[1] = 575;
}
break;
case Difficulty.Hard:
if (diagonalRows)
{
difficultyRange[0] = 660;
difficultyRange[1] = 775;
}
else
{
difficultyRange[0] = 575;
difficultyRange[1] = 630;
}
break;
case Difficulty.VeryHard:
if (diagonalRows)
{
difficultyRange[0] = 775;
difficultyRange[1] = 950;
}
else
{
difficultyRange[0] = 630;
difficultyRange[1] = 700;
}
break;
case Difficulty.ExtremelyHard:
if (diagonalRows)
{
difficultyRange[0] = 950;
difficultyRange[1] = 1500;
}
else
{
difficultyRange[0] = 700;
difficultyRange[1] = 1500;
}
break;
}
}
while (true)
{
RemoveRandomIntegers(sudokuArray);
if (CheckIfDifficultyMet(difficulty, sudokuArray) == 1)
{
var p = Solver.RateSudokuGrid(this, Solver.CopySudoku(sudokuArray));
if (p >= difficultyRange[0] && p <= difficultyRange[1])
{
rating = p;
break;
}
}
sudokuArray = Solver.CopySudoku(SudokuCompleteArray);
}
SudokuIncompleteArray = Solver.CopySudoku(sudokuArray);
}
private short CheckIfDifficultyMet(Difficulty difficulty, int[,] sudokuArray)
{
//-1: too hard,
//0: too easy,
//1: met,
var tooEasy = false;
int[] numbersPerBox;
int[] instancesOfNumbers;
int[] numbersPerRow;
int[] overallNumbers;
switch (difficulty)
{
case Difficulty.Easy:
numbersPerBox = new int[2] {
2, 9
};
instancesOfNumbers = new int[2] {
1, 9
};
numbersPerRow = new int[2] {
1, 9
};
overallNumbers = new int[2] {
30, 40
};
break;
case Difficulty.Normal:
numbersPerBox = new int[2] {
1, 8
};
instancesOfNumbers = new int[2] {
1, 7
};
numbersPerRow = new int[2] {
1, 7
};
overallNumbers = new int[2] {
25, 30
};
break;
case Difficulty.Hard:
numbersPerBox = new int[2] {
1, 5
};
instancesOfNumbers = new int[2] {
0, 7
};
numbersPerRow = new int[2] {
0, 5
};
overallNumbers = new int[2] {
20, 25
};
break;
case Difficulty.VeryHard:
numbersPerBox = new int[2] {
0, 7
};
instancesOfNumbers = new int[2] {
0, 7
};
numbersPerRow = new int[2] {
0, 7
};
overallNumbers = new int[2] {
17, 25
};
break;
case Difficulty.ExtremelyHard:
numbersPerBox = new int[2] {
0, 9
};
instancesOfNumbers = new int[2] {
0, 9
};
numbersPerRow = new int[2] {
0, 9
};
overallNumbers = new int[2] {
15, 25
};
break;
default:
numbersPerBox = new int[2] {
2, 9
};
instancesOfNumbers = new int[2] {
1, 9
};
numbersPerRow = new int[2] {
1, 9
};
overallNumbers = new int[2] {
30, 35
};
break;
}
if (!diagonalRows)
{
overallNumbers[1] += 3;
}
int n;
if (!CheckIfProtectedPatternsAreSafe(sudokuArray))
{
return(-1);
}
foreach (var i in CreateListOfAllIntegers())
{
n = Solver.CountInstancesOfInteger(i, sudokuArray);
if (n > instancesOfNumbers[1])
{
tooEasy = true;
}
if (n < instancesOfNumbers[0])
{
return(-1);
}
n = Solver.CountIntegersOfRow(i - 1, sudokuArray);
if (n > numbersPerRow[1])
{
tooEasy = true;
}
if (n < numbersPerRow[0])
{
return(-1);
}
n = Solver.CountIntegersOfColumn(i - 1, sudokuArray);
if (n > numbersPerRow[1])
{
tooEasy = true;
}
if (n < numbersPerRow[0])
{
return(-1);
}
n = Solver.CountIntegersOfBox(SudokuBoxArrayList[i - 1], sudokuArray);
if (n > numbersPerBox[1])
{
tooEasy = true;
}
if (n < numbersPerBox[0])
{
return(-1);
}
}
n = Solver.CountIntegersOfGrid(sudokuArray);
if (n > overallNumbers[1])
{
tooEasy = true;
}
if (n < overallNumbers[0])
{
return(-1);
}
if (tooEasy)
{
return(0);
}
return(1);
}
public int[,] GetCopyOfCompleteSudokuArray()
{
return(Solver.CopySudoku(SudokuCompleteArray));
}
/// <summary>Generates a random Sudoku puzzle.</summary>
/// <returns>The generated results.</returns>
private static SolverResults GenerateOne(GeneratorOptions options)
{
// Generate a full solution randomly, using the solver to solve a completely empty grid.
// For this, we'll use the elimination techniques that yield fast solving.
PuzzleState solvedState = new PuzzleState();
SolverOptions solverOptions = new SolverOptions();
solverOptions.MaximumSolutionsToFind = 1;
solverOptions.EliminationTechniques = new List <EliminationTechnique> {
new NakedSingleTechnique()
};
solverOptions.AllowBruteForce = true;
SolverResults newSolution = Solver.Solve(solvedState, solverOptions);
// Create options to use for removing filled cells from the complete solution.
// MaximumSolutionsToFind is set to 2 so that we look for more than 1, but there's no
// need in continuing once we know there's more than 1, so 2 is a find value to use.
solverOptions.MaximumSolutionsToFind = 2;
solverOptions.AllowBruteForce =
!options.MaximumNumberOfDecisionPoints.HasValue || options.MaximumNumberOfDecisionPoints > 0;
solverOptions.EliminationTechniques = solverOptions.AllowBruteForce ?
new List <EliminationTechnique> {
new NakedSingleTechnique()
} : options.Techniques; // For perf: if brute force is allowed, techniques don't matter!
// Now that we have a full solution, we want to randomly remove values from cells
// until we get to a point where there is not a unique solution for the puzzle. The
// last puzzle state that did have a unique solution can then be used.
PuzzleState newPuzzle = newSolution.Puzzle;
// Get a random ordering of the cells in which to test their removal
Point [] filledCells = GetRandomCellOrdering(newPuzzle);
// Do we want to ensure symmetry?
int filledCellCount = options.EnsureSymmetry && (filledCells.Length % 2 != 0) ? filledCells.Length - 1 : filledCells.Length;
// If ensuring symmetry...
if (options.EnsureSymmetry)
{
// Find the middle cell and put it at the end of the ordering
for (int i = 0; i < filledCells.Length - 1; i++)
{
Point p = filledCells[i];
if (p.X == newPuzzle.GridSize - p.X - 1 &&
p.Y == newPuzzle.GridSize - p.Y - 1)
{
Point temp = filledCells[i];
filledCells[i] = filledCells[filledCells.Length - 1];
filledCells[filledCells.Length - 1] = temp;
}
}
// Modify the random ordering so that paired symmetric cells are next to each other
// i.e. filledCells[i] and filledCells[i+1] are symmetric pairs
for (int i = 0; i < filledCells.Length - 1; i += 2)
{
Point p = filledCells[i];
Point sp = new Point(newPuzzle.GridSize - p.X - 1, newPuzzle.GridSize - p.Y - 1);
for (int j = i + 1; j < filledCells.Length; j++)
{
if (filledCells[j].Equals(sp))
{
Point temp = filledCells[i + 1];
filledCells[i + 1] = filledCells[j];
filledCells[j] = temp;
break;
}
}
}
// In the order of the array, try to remove each pair from the puzzle and see if it's
// still solvable and in a valid way. If it is, greedily leave those cells out of the puzzle.
// Otherwise, skip them.
byte [] oldValues = new byte[2];
for (int filledCellNum = 0;
filledCellNum < filledCellCount && newPuzzle.NumberOfFilledCells > options.MinimumFilledCells;
filledCellNum += 2)
{
// Store the old value so we can put it back if necessary,
// then wipe it out of the cell
oldValues[0] = newPuzzle[filledCells[filledCellNum]].Value;
oldValues[1] = newPuzzle[filledCells[filledCellNum + 1]].Value;
newPuzzle[filledCells[filledCellNum]] = null;
newPuzzle[filledCells[filledCellNum + 1]] = null;
// Check to see whether removing it left us in a good position (i.e. a
// single-solution puzzle that doesn't violate any of the generation options)
SolverResults newResults = Solver.Solve(newPuzzle, solverOptions);
if (!IsValidRemoval(newPuzzle, newResults, options))
{
newPuzzle[filledCells[filledCellNum]] = oldValues[0];
newPuzzle[filledCells[filledCellNum + 1]] = oldValues[1];
}
}
// If there are an odd number of cells in the puzzle (which there will be
// as everything we're doing is 9x9, 81 cells), try to remove the odd
// cell that doesn't have a pairing. This will be the middle cell.
if (filledCells.Length % 2 != 0)
{
// Store the old value so we can put it back if necessary,
// then wipe it out of the cell
int filledCellNum = filledCells.Length - 1;
byte oldValue = newPuzzle[filledCells[filledCellNum]].Value;
newPuzzle[filledCells[filledCellNum]] = null;
// Check to see whether removing it left us in a good position (i.e. a
// single-solution puzzle that doesn't violate any of the generation options)
SolverResults newResults = Solver.Solve(newPuzzle, solverOptions);
if (!IsValidRemoval(newPuzzle, newResults, options))
{
newPuzzle[filledCells[filledCellNum]] = oldValue;
}
}
}
// otherwise, it's much easier.
else
{
// Look at each cell in the random ordering. Try to remove it.
// If it works to remove it, do so greedily. Otherwise, skip it.
for (int filledCellNum = 0;
filledCellNum < filledCellCount && newPuzzle.NumberOfFilledCells > options.MinimumFilledCells;
filledCellNum++)
{
// Store the old value so we can put it back if necessary,
// then wipe it out of the cell
byte oldValue = newPuzzle[filledCells[filledCellNum]].Value;
newPuzzle[filledCells[filledCellNum]] = null;
// Check to see whether removing it left us in a good position (i.e. a
// single-solution puzzle that doesn't violate any of the generation options)
SolverResults newResults = Solver.Solve(newPuzzle, solverOptions);
if (!IsValidRemoval(newPuzzle, newResults, options))
{
newPuzzle[filledCells[filledCellNum]] = oldValue;
}
}
}
// Make sure to now use the techniques specified by the user to score this thing
solverOptions.EliminationTechniques = options.Techniques;
SolverResults finalResult = Solver.Solve(newPuzzle, solverOptions);
// Return the best puzzle we could come up with
newPuzzle.Difficulty = options.Difficulty;
return(new SolverResults(PuzzleStatus.Solved, newPuzzle, finalResult.NumberOfDecisionPoints, finalResult.UseOfTechniques));
}
public static void Solve(Board board)
{
var solver = new Solver(board);
solver.Solve();
}