java用数组实现随机布雷 编程要求：在N*N的二维表格中实现随机布雷，布雷个数M预先定义。如果是雷，显示字符@，如果不是雷，显示本格周围雷个数的统计，编程提示（1）Block类：boolean isMine表示是不是雷，int num表示周围雷的个数。（2）用三重循环实现周围雷个数的统计

以下是Java实现随机布雷的代码：

import java.util.Random;

public class MineSweeper {
    private Block[][] mineField; // 雷区
    private int size; // 大小
    private int mineCount; // 雷数

    public MineSweeper(int size, int mineCount) {
        this.size = size;
        this.mineCount = mineCount;
        mineField = new Block[size][size];
        initMineField();
        setMines();
        setNums();
    }

    // 初始化雷区
    private void initMineField() {
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                mineField[i][j] = new Block();
            }
        }
    }

    // 放置雷
    private void setMines() {
        Random random = new Random();
        int count = 0;
        while (count < mineCount) {
            int x = random.nextInt(size);
            int y = random.nextInt(size);
            if (!mineField[x][y].isMine()) {
                mineField[x][y].setMine(true);
                count++;
            }
        }
    }

    // 统计周围雷的数量
    private void setNums() {
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                if (!mineField[i][j].isMine()) {
                    int count = 0;
                    for (int row = i - 1; row <= i + 1; row++) {
                        for (int col = j - 1; col <= j + 1; col++) {
                            if (row >= 0 && row < size && col >= 0 && col < size) {
                                if (mineField[row][col].isMine()) {
                                    count++;
                                }
                            }
                        }
                    }
                    mineField[i][j].setNum(count);
                }
            }
        }
    }

    // 打印雷区
    public void printMineField() {
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                if (mineField[i][j].isMine()) {
                    System.out.print("@ ");
                } else {
                    System.out.print(mineField[i][j].getNum() + " ");
                }
            }
            System.out.println();
        }
    }

    public static void main(String[] args) {
        MineSweeper mineSweeper = new MineSweeper(10, 10);
        mineSweeper.printMineField();
    }
}

class Block {
    private boolean isMine; // 是否是雷
    private int num; // 周围雷的数量

    public boolean isMine() {
        return isMine;
    }

    public void setMine(boolean isMine) {
        this.isMine = isMine;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }
}

代码中使用了三重循环来实现周围雷数的统计，首先遍历雷区中每个非雷方块，然后再遍历该方块周围的8个方块，统计周围雷数。如果遍历到的方块超出了雷区的边界，则不计入统计。