6X6数独 java

6x6数独是一种基于数字的逻辑游戏，目标是在一个6x6的方格中填入数字1到6，使得每一行、每一列和每个3x2的小方格内都包含了1到6的数字，且每个数字在每一行、每一列和每个小方格内都只出现一次。

以下是一个简单的Java代码示例，用于解决6x6数独问题：

public class SudokuSolver {
    private int[][] grid;

    public SudokuSolver(int[][] grid) {
        this.grid = grid;
    }

    public boolean solve() {
        for (int row = 0; row < 6; row++) {
            for (int col = 0; col < 6; col++) {
                if (grid[row][col] == 0) {
                    for (int num = 1; num <= 6; num++) {
                        if (isValid(row, col, num)) {
                            grid[row][col] = num;
                            if (solve()) {
                                return true;
                            }
                            grid[row][col] = 0;
                        }
                    }
                    return false;
                }
            }
        }
        return true;
    }

    private boolean isValid(int row, int col, int num) {
        for (int i = 0; i < 6; i++) {
            if (grid[row][i] == num || grid[i][col] == num) {
                return false;
            }
        }
        int startRow = row - row % 2;
        int startCol = col - col % 3;
        for (int i = startRow; i < startRow + 2; i++) {
            for (int j = startCol; j < startCol + 3; j++) {
                if (grid[i][j] == num) {
                    return false;
                }
            }
        }
        return true;
    }

    public void printSolution() {
        for (int row = 0; row < 6; row++) {
            for (int col = 0; col < 6; col++) {
                System.out.print(grid[row][col] + " ");
            }
            System.out.println();
        }
    }

    public static void main(String[] args) {
        int[][] grid = {
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0}
        };

        SudokuSolver solver = new SudokuSolver(grid);
        if (solver.solve()) {
            solver.printSolution();
        } else {
            System.out.println("No solution exists.");
        }
    }
}

这段代码使用递归的方式来解决数独问题。它通过尝试在每个空格中填入数字，并检查是否满足数独的规则，如果满足则继续递归地解决下一个空格，直到所有空格都被填满或者无解。