/**
* Sudoku puzzle generator.
*
* @return Sudoku puzzle if process finished correctly, otherwise null.
*/
public int[,] generate() {
if (generatorState != GENERATOR_INIT_FINISHED) {
generatorState = GENERATOR_GEN_NOT_STARTED;
addMessage("(SudokuGenerator) Generation process not started due to incorrect initialization.", MSG_ERROR);
return null;
}
long solvingStartTime = DateTimeX.currentTimeMillis();
generatorState = GENERATOR_GEN_STARTED;
addMessage("(SudokuGenerator) Generation process started.", MSG_INFO);
if (randomizeFilledCells == true)
addMessage("(SudokuGenerator) >>> Will randomize filled cells within cells with the same impact.", MSG_INFO);
boardCells = new BoardCell[BOARD_CELLS_NUMBER];
int cellIndex = 0;
for (int i = 0; i < BOARD_SIZE; i++)
for (int j = 0; j < BOARD_SIZE; j++) {
int d = sudokuBoard[i, j];
if (d != CELL_EMPTY) {
boardCells[cellIndex] = new BoardCell(i, j, d);
cellIndex++;
}
}
int filledCells = cellIndex;
for (int i = 0; i < BOARD_SIZE; i++)
for (int j = 0; j < BOARD_SIZE; j++) {
int d = sudokuBoard[i, j];
if (d == CELL_EMPTY) {
boardCells[cellIndex] = new BoardCell(i, j, d);
cellIndex++;
}
}
updateDigitsStillFreeCounts();
sortBoardCells(0, filledCells - 1);
do {
int r = 0;
int i = boardCells[r].rowIndex;
int j = boardCells[r].colIndex;
int d = sudokuBoard[i, j];
sudokuBoard[i, j] = CELL_EMPTY;
SudokuSolver s = new SudokuSolver(sudokuBoard);
if (s.checkIfUniqueSolution() != SudokuSolver.SOLUTION_UNIQUE)
sudokuBoard[i, j] = d;
int lastIndex = filledCells - 1;
if (r < lastIndex) {
BoardCell b1 = boardCells[r];
BoardCell b2 = boardCells[lastIndex];
boardCells[lastIndex] = b1;
boardCells[r] = b2;
}
filledCells--;
updateDigitsStillFreeCounts();
if (filledCells > 0) sortBoardCells(0, filledCells - 1);
} while (filledCells > 0);
long solvingEndTime = DateTimeX.currentTimeMillis();
computingTime = (solvingEndTime - solvingStartTime) / 1000.0;
generatorState = GENERATOR_GEN_FINISHED;
addMessage("(SudokuGenerator) Generation process finished, computing time: " + computingTime + " s.", MSG_INFO);
return sudokuBoard;
}
/**
* Calculates difficulty of Sudoku puzzle. Returned difficulty level is an average
* of number of closed routes while performing recursive steps in order to find solution.
* This is multi-threading procedure.
*
* @param sudokuPuzzle Sudoku puzzle to be rated.
* @return If puzzle does not contain an error then difficulty rating is returned.
* If puzzle contains obvious error then {@link ErrorCodes#SUDOKUSTORE_CALCULATEPUZZLERATING_PUZZLE_ERROR}.
* If puzzle has no solutions then {@link ErrorCodes#SUDOKUSTORE_CALCULATEPUZZLERATING_NO_SOLUTION}.
* If solution is non-unique then {@link ErrorCodes#SUDOKUSTORE_CALCULATEPUZZLERATING_NON_UNIQUE_SOLUTION}.
*/
public static int calculatePuzzleRating(int[,] sudokuPuzzle) {
if (checkPuzzle(sudokuPuzzle) == false)
return ErrorCodes.SUDOKUSTORE_CALCULATEPUZZLERATING_PUZZLE_ERROR;
SudokuSolver s = new SudokuSolver(sudokuPuzzle);
int solType = s.checkIfUniqueSolution();
if (solType == SudokuSolver.SOLUTION_NOT_EXISTS)
return ErrorCodes.SUDOKUSTORE_CALCULATEPUZZLERATING_NO_SOLUTION;
if (solType == SudokuSolver.SOLUTION_NON_UNIQUE)
return ErrorCodes.SUDOKUSTORE_CALCULATEPUZZLERATING_NON_UNIQUE_SOLUTION;
/*
* Multi-threading implementation
*/
int threadIterNum = RATING_DEF_NUM_OF_ITERATIONS / THREADS_NUMBER;
int[,] results = new int[THREADS_NUMBER, threadIterNum];
Runner[] runners = new Runner[THREADS_NUMBER];
Thread[] threads = new Thread[THREADS_NUMBER];
for (int t = 0; t < THREADS_NUMBER; t++) {
runners[t] = new Runner(t, threadIterNum, sudokuPuzzle, results);
threads[t] = new Thread(runners[t].run);
}
for (int t = 0; t < THREADS_NUMBER; t++) {
threads[t].Start();
}
for (int t = 0; t < THREADS_NUMBER; t++) {
try {
threads[t].Join();
} catch (ThreadInterruptedException e) {
Console.WriteLine(e.StackTrace);
return ErrorCodes.SUDOKUSTORE_CALCULATEPUZZLERATING_THREADS_JOIN_FAILED;
}
}
int sum = 0;
for (int t = 0; t < THREADS_NUMBER; t++)
for (int i = 0; i < threadIterNum; i++)
sum+=results[t, i];
return sum / (THREADS_NUMBER * threadIterNum);
}
/**
* Board initialization method.
* @param initBoard Initial board.
* @param info The string to pass to the msg builder.
*/
private void boardInit(int[,] initBoard, String info) {
SudokuSolver puzzle;
if ((initBoard == null) && (generateRandomBoard == true)) {
puzzle = new SudokuSolver(SudokuPuzzles.PUZZLE_EMPTY);
puzzle.solve();
if (puzzle.getSolvingState() == SudokuSolver.SOLVING_STATE_SOLVED) {
sudokuBoard = puzzle.solvedBoard;
addMessage("(SudokuGenerator) Generator initialized using random board (" + info + ").", MSG_INFO);
generatorState = GENERATOR_INIT_FINISHED;
return;
} else {
addMessage("(SudokuGenerator) Generator initialization using random board (" + info + ") failed. Board with error?", MSG_ERROR);
addMessage(puzzle.getLastErrorMessage(), MSG_ERROR);
generatorState = GENERATOR_INIT_FAILED;
return;
}
}
if (SudokuStore.checkPuzzle(initBoard) == false) {
generatorState = GENERATOR_INIT_FAILED;
addMessage("(SudokuGenerator) Generator initialization (" + info + ") failed. Board with error?", MSG_ERROR);
return;
}
if (solveBeforeGeneration == true) {
puzzle = new SudokuSolver(initBoard);
puzzle.solve();
if (puzzle.getSolvingState() == SudokuSolver.SOLVING_STATE_SOLVED) {
sudokuBoard = puzzle.solvedBoard;
addMessage("(SudokuGenerator) Generator initialized usign provided board + finding solution (" + info + ").", MSG_INFO);
generatorState = GENERATOR_INIT_FINISHED;
return;
} else {
addMessage("(SudokuGenerator) Generator initialization usign provided board + finding solution (" + info + ") failed. Board with error?", MSG_ERROR);
addMessage(puzzle.getLastErrorMessage(), MSG_ERROR);
generatorState = GENERATOR_INIT_FAILED;
return;
}
}
int[,] board = initBoard;
puzzle = new SudokuSolver(board);
if (puzzle.checkIfUniqueSolution() == SudokuSolver.SOLUTION_UNIQUE) {
sudokuBoard = board;
addMessage("(SudokuGenerator) Generator initialized usign provided board (" + info + ").", MSG_INFO);
generatorState = GENERATOR_INIT_FINISHED;
return;
} else {
addMessage("(SudokuGenerator) Generator initialization usign provided board (" + info + ") failed. Solution not exists or is non unique.", MSG_ERROR);
addMessage(puzzle.getLastErrorMessage(), MSG_ERROR);
generatorState = GENERATOR_INIT_FAILED;
return;
}
}