操作系统死锁避免实验c语言代码

根据提供的引用内容，可以介绍一下《操作系统》第四版汤小丹等人编著的C语言代码实现银行家算法。代码可以自行设置进程相关数据，显示安全序列，可以多次申请资源查看是否安全。以下是代码示例：

#include <stdio.h>
#include <stdlib.h>
#define N 100
#define M 100

int available[M], max[N][M], allocation[N][M], need[N][M], request[M], finish[N], work[M], safe[N];
int n, m, num = 0;

void init() {
    int i, j;
    printf("请输入进程数n和资源种类数m：\n");
    scanf("%d%d", &n, &m);
    printf("请输入每个进程最大需求矩阵：\n");
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            scanf("%d", &max[i][j]);
        }
    }
    printf("请输入每个进程已分配矩阵：\n");
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            scanf("%d", &allocation[i][j]);
        }
    }
    printf("请输入每个进程还需要矩阵：\n");
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            need[i][j] = max[i][j] - allocation[i][j];
        }
    }
    printf("请输入每个资源可用数：\n");
    for (i = 0; i < m; i++) {
        scanf("%d", &available[i]);
    }
}

void show() {
    int i, j;
    printf("进程数n=%d, 资源种类数m=%d\n", n, m);
    printf("每个进程最大需求矩阵：\n");
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            printf("%d ", max[i][j]);
        }
        printf("\n");
    }
    printf("每个进程已分配矩阵：\n");
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            printf("%d ", allocation[i][j]);
        }
        printf("\n");
    }
    printf("每个进程还需要矩阵：\n");
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            printf("%d ", need[i][j]);
        }
        printf("\n");
    }
    printf("每个资源可用数：\n");
    for (i = 0; i < m; i++) {
        printf("%d ", available[i]);
    }
    printf("\n");
}

int safety() {
    int i, j, k, flag, count = 0;
    for (i = 0; i < n; i++) {
        finish[i] = 0;
    }
    for (i = 0; i < m; i++) {
        work[i] = available[i];
    }
    while (count < n) {
        flag = 0;
        for (i = 0; i < n; i++) {
            if (finish[i] == 0) {
                for (j = 0; j < m; j++) {
                    if (need[i][j] > work[j]) {
                        break;
                    }
                }
                if (j == m) {
                    for (k = 0; k < m; k++) {
                        work[k] += allocation[i][k];
                    }
                    finish[i] = 1;
                    safe[count] = i;
                    count++;
                    flag = 1;
                }
            }
        }
        if (flag == 0) {
            return 0;
        }
    }
    return 1;
}

void request_res() {
    int i, j, p;
    printf("请输入请求资源的进程编号：\n");
    scanf("%d", &p);
    printf("请输入请求资源向量：\n");
    for (i = 0; i < m; i++) {
        scanf("%d", &request[i]);
    }
    for (i = 0; i < m; i++) {
        if (request[i] > need[p][i]) {
            printf("请求资源大于进程还需要的资源！\n");
            return;
        }
        if (request[i] > available[i]) {
            printf("请求资源大于系统可用的资源！\n");
            return;
        }
    }
    for (i = 0; i < m; i++) {
        available[i] -= request[i];
        allocation[p][i] += request[i];
        need[p][i] -= request[i];
    }
    if (safety() == 1) {
        printf("同意分配请求！\n");
    } else {
        printf("拒绝分配请求！\n");
        for (i = 0; i < m; i++) {
            available[i] += request[i];
            allocation[p][i] -= request[i];
            need[p][i] += request[i];
        }
    }
}

int main() {
    int i;
    init();
    show();
    if (safety() == 1) {
        printf("系统是安全的！\n");
        printf("安全序列为：");
        for (i = 0; i < n; i++) {
            printf("%d ", safe[i]);
        }
        printf("\n");
    } else {
        printf("系统是不安全的！\n");
    }
    request_res();
    return 0;
}