银行家算法python语言

银行家算法是一种避免死锁的算法，它通过动态地分配资源来避免死锁的发生。下面是一个简单的银行家算法的Python实现：

# 定义银行家算法类
class BankerAlgorithm:
    def __init__(self, available, max, allocation):
        self.available = available  # 可用资源
        self.max = max  # 最大需求矩阵
        self.allocation = allocation  # 已分配矩阵
        self.need = self.max - self.allocation  # 需求矩阵
        self.safe_sequence = []  # 安全序列

    # 检查当前状态是否安全
    def is_safe(self):
        work = self.available.copy()
        finish = [False] * len(self.max)
        while False in finish:
            found = False
            for i in range(len(self.max)):
                if not finish[i] and all(self.need[i] <= work):
                    work += self.allocation[i]
                    finish[i] = True
                    self.safe_sequence.append(i)
                    found = True
            if not found:
                return False
        return True

    # 请求资源
    def request(self, request):
        if all(request <= self.need) and all(request <= self.available):
            self.available -= request
            self.allocation += request
            self.need = self.max - self.allocation
            if self.is_safe():
                return True
            else:
                self.available += request
                self.allocation -= request
                self.need = self.max - self.allocation
                return False
        else:
            return False

    # 释放资源
    def release(self, release):
        self.available += release
        self.allocation -= release
        self.need = self.max - self.allocation

# 测试
if __name__ == '__main__':
    available = [3, 3, 2]
    max = [[7, 5, 3], [3, 2, 2], [9, 0, 2]]
    allocation = [[0, 1, 0], [2, 0, 0], [3, 0, 2]]
    banker = BankerAlgorithm(available, max, allocation)
    request = [1, 0, 2]
    if banker.request(request):
        print("Request granted")
        print("Safe sequence:", banker.safe_sequence)
    else:
        print("Request denied")

以上代码实现了银行家算法的主要功能，包括检查当前状态是否安全、请求资源和释放资源。在测试部分，我们定义了一个初始状态，然后请求一些资源，如果请求被允许，就输出安全序列，否则输出请求被拒绝。