使用c语言实现银行家算法

以下是使用C语言实现银行家算法的示例代码：

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

#define MAX_PROCESS 10
#define MAX_RESOURCE 10

int available[MAX_RESOURCE];int max[MAX_PROCESS][MAX_RESOURCE];
int allocation[MAX_PROCESS][MAX_RESOURCE];
int need[MAX_PROCESS][MAX_RESOURCE];
bool finish[MAX_PROCESS];

int num_process, num_resource;

bool is_safe() {
    int work[MAX_RESOURCE];
    for (int i = 0; i < num_resource; i++) {
        work[i] = available[i];
    }
    bool finish_copy[MAX_PROCESS];
    for (int i = 0; i < num_process; i++) {
        finish_copy[i] = finish[i];
    }
    bool found;
    do {
        found = false;
        for (int i = 0; i < num_process; i++) {
            if (!finish_copy[i]) {
                bool enough_resource = true;
                for (int j = 0; j < num_resource; j++) {
                    if (need[i][j] > work[j]) {
                        enough_resource = false;
                        break;
                    }
                }
                if (enough_resource) {
                    finish_copy[i] = true;
                    found = true;
                    for (int j = 0; j < num_resource; j++) {
                        work[j] += allocation[i][j];
                    }
                }
            }
        }
    } while (found);
    for (int i = 0; i < num_process; i++) {
        if (!finish_copy[i]) {
            return false;
        }
    }
    return true;
}

bool request_resources(int process_id, int request[]) {
    for (int i = 0; i < num_resource; i++) {
        if (request[i] > need[process_id][i] || request[i] > available[i]) {
            return false;
        }
    }
    for (int i = 0; i < num_resource; i++) {
        available[i] -= request[i];
        allocation[process_id][i] += request[i];
        need[process_id][i] -= request[i];
    }
    if (is_safe()) {
        return true;
    } else {
        for (int i = 0; i < num_resource; i++) {
            available[i] += request[i];
            allocation[process_id][i] -= request[i];
            need[process_id][i] += request[i];
        }
        return false;
    }
}

int main() {
    printf("Enter the number of processes: ");
    scanf("%d", &num_process);
    printf("Enter the number of resources: ");
    scanf("%d", &num_resource);
    printf("Enter the available resources: ");
    for (int i = 0; i < num_resource; i++) {
        scanf("%d", &available[i]);
    }
    printf("Enter the maximum demand of each process: ");
    for (int i = 0; i < num_process; i++) {
        for (int j = 0; j < num_resource; j++) {
            scanf("%d", &max[i][j]);
        }
    }
    printf("Enter the allocation of each process: ");
    for (int i = 0; i < num_process; i++) {
        for (int j = 0; j < num_resource; j++) {
            scanf("%d", &allocation[i][j]);
            need[i][j] = max[i][j] - allocation[i][j];
        }
        finish[i] = false;
    }
    if (is_safe()) {
        printf("The system is in a safe state.\n");
    } else {
        printf("The system is in an unsafe state.\n");
    }
    int process_id;
    printf("Enter the process id to request resources: ");
    scanf("%d", &process_id);
    int request[MAX_RESOURCE];
    printf("Enter the request: ");
    for (int i = 0; i < num_resource; i++) {
        scanf("%d", &request[i]);
    }
    if (request_resources(process_id, request)) {
        printf("The request is granted.\n");
    } else {
        printf("The request is denied.\n");
    }
    return 0;
}