银行家算法 c语言代码

银行家算法是一种避免死锁的算法，以下是使用 C 语言实现的代码：

#include <stdio.h>
#include <stdbool.h>

#define MAX_RESOURCES 5

int available_resources = MAX_RESOURCES;
int allocated_resources = 0;
int max_resources = MAX_RESOURCES;
int needed_resources = 0;

bool request_resources(int requested_resources) {
    // Check if there are enough resources available
    if (requested_resources > available_resources) {
        printf("Not enough resources available.\n");
        return false;
    }

    // Check if the request will cause the system to be in a safe state
    if (requested_resources > max_resources - allocated_resources) {
        printf("Request can't be granted.\n");
        return false;
    }

    // Grant the request
    available_resources -= requested_resources;
    allocated_resources += requested_resources;
    needed_resources = max_resources - allocated_resources;

    printf("Request granted.\n");
    printf("Available resources: %d\n", available_resources);
    printf("Allocated resources: %d\n", allocated_resources);
    printf("Needed resources: %d\n", needed_resources);

    return true;
}

void release_resources(int released_resources) {
    // Release the resources
    available_resources += released_resources;
    allocated_resources -= released_resources;
    needed_resources = max_resources - allocated_resources;

    printf("Resources released.\n");
    printf("Available resources: %d\n", available_resources);
    printf("Allocated resources: %d\n", allocated_resources);
    printf("Needed resources: %d\n", needed_resources);
}

int main() {
    // Request some resources
    request_resources(2);

    // Release some resources
    release_resources(1);

    return 0;
}

这段代码实现了银行家算法的基本逻辑。首先定义了可用资源、已分配资源、最大资源和需要资源等变量，然后定义了请求资源和释放资源的函数。在请求资源函数中，会检查是否有足够的资源可用，以及请求是否会导致系统处于不安全状态，如果请求合法则会分配资源。在释放资源函数中，会释放资源并更新各个变量的值。最后在主函数中演示了如何使用这些函数。