银行家算法java语言

以下是一个简单的银行家算法的Java实现：

public class BankerAlgorithm {
    private int[][] need; // 需求矩阵
    private int[][] allocation; // 分配矩阵
    private int[] available; // 可用资源向量
    private int[] safeSequence; // 安全序列

    public BankerAlgorithm(int[][] need, int[][] allocation, int[] available) {
        this.need = need;
        this.allocation = allocation;
        this.available = available;
        this.safeSequence = new int[allocation.length];
    }

    public boolean isSafe() {
        boolean[] finish = new boolean[allocation.length];
        int[] work = available.clone();

        int count = 0; // 安全序列计数器
        while (count < allocation.length) {
            boolean find = false;
            for (int i = 0; i < allocation.length; i++) {
                if (!finish[i] && lessEqual(need[i], work)) {
                    for (int j = 0; j < allocation[i].length; j++) {
                        work[j] += allocation[i][j];
                    }
                    finish[i] = true;
                    safeSequence[count++] = i;
                    find = true;
                }
            }
            if (!find) {
                return false; // 找不到满足条件的进程，说明不安全
            }
        }
        return true;
    }

    public int[] getSafeSequence() {
        return safeSequence;
    }

    private boolean lessEqual(int[] a, int[] b) {
        for (int i = 0; i < a.length; i++) {
            if (a[i] > b[i]) {
                return false;
            }
        }
        return true;
    }
}

使用时，可以按照以下步骤：

1. 定义需求矩阵、分配矩阵和可用资源向量。
2. 创建`BankerAlgorithm`对象，传入上述三个参数。
3. 调用`isSafe()`方法判断是否安全，如果返回true，则调用`getSafeSequence()`方法获取安全序列。

示例代码：

public static void main(String[] args) {
    int[][] need = {{3, 2, 2}, {6, 1, 3}, {3, 1, 4}, {4, 2, 2}, {4, 3, 3}};
    int[][] allocation = {{0, 1, 0}, {2, 0, 0}, {3, 0, 2}, {2, 1, 1}, {0, 0, 2}};
    int[] available = {1, 0, 2};

    BankerAlgorithm banker = new BankerAlgorithm(need, allocation, available);
    if (banker.isSafe()) {
        int[] safeSequence = banker.getSafeSequence();
        System.out.println("Safe sequence: " + Arrays.toString(safeSequence));
    } else {
        System.out.println("Not safe!");
    }
}