Java中的数独电路板生成逻辑

public class SudokuGenerator {
    private int[][] board;

    public SudokuGenerator() {
        board = new int[9][9];
    }

    public void generateBoard() {
        generatePartialBoard(0, 0);
    }

    private boolean generatePartialBoard(int row, int col) {
        if (col == 9) {
            col = 0;
            row++;
            if (row == 9) {
                return true; // 所有单元格都已填满，生成完成
            }
        }

        if (board[row][col] != 0) {
            return generatePartialBoard(row, col + 1); // 当前单元格已有数字，跳到下一个单元格
        }

        List<Integer> numbers = new ArrayList<>();
        for (int i = 1; i <= 9; i++) {
            numbers.add(i);
        }
        Collections.shuffle(numbers); // 随机打乱数字顺序

        for (int number : numbers) {
            if (isValidPlacement(row, col, number)) {
                board[row][col] = number;
                if (generatePartialBoard(row, col + 1)) {
                    return true; // 递归调用填充下一个单元格
                }
                board[row][col] = 0; // 回溯，重置当前单元格的数字
            }
        }

        return false; // 无法找到合适的数字，回溯到上一个单元格
    }

    private boolean isValidPlacement(int row, int col, int number) {
        // 检查当前数字在行中是否重复
        for (int i = 0; i < 9; i++) {
            if (board[row][i] == number) {
                return false;
            }
        }

        // 检查当前数字在列中是否重复
        for (int i = 0; i < 9; i++) {
            if (board[i][col] == number) {
                return false;
            }
        }

        // 检查当前数字在3x3子方格中是否重复
        int startRow = row - row % 3;
        int startCol = col - col % 3;
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                if (board[startRow + i][startCol + j] == number) {
                    return false;
                }
            }
        }

        return true; // 当前数字在行、列和子方格中均不重复
    }

    public void printBoard() {
        for (int i = 0; i < 9; i++) {
            for (int j = 0; j < 9; j++) {
                System.out.print(board[i][j] + " ");
            }
            System.out.println();
        }
    }

    public static void main(String[] args) {
        SudokuGenerator generator = new SudokuGenerator();
        generator.generateBoard();
        generator.printBoard();
    }
}