银行家算法模拟实验c语言

#include <stdio.h>
#include <stdlib.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];
int work[MAX_RESOURCE];
int finish[MAX_PROCESS];
int request[MAX_RESOURCE];
int num_process, num_resource;

void init() {
    int i, j;
    printf("请输入进程数和资源数：\n");
    scanf("%d%d", &num_process, &num_resource);
    printf("请输入每个进程最大需求量：\n");
    for (i = 0; i < num_process; i++) {
        for (j = 0; j < num_resource; j++) {
            scanf("%d", &max[i][j]);
        }
    }
    printf("请输入每个进程已分配量：\n");
    for (i = 0; i < num_process; i++) {
        for (j = 0; j < num_resource; j++) {
            scanf("%d", &allocation[i][j]);
            need[i][j] = max[i][j] - allocation[i][j];
        }
    }
    printf("请输入每个资源的总量：\n");
    for (i = 0; i < num_resource; i++) {
        scanf("%d", &available[i]);
    }
}

int safety_check() {
    int i, j, k;
    for (i = 0; i < num_resource; i++) {
        work[i] = available[i];
    }
    for (i = 0; i < num_process; i++) {
        finish[i] = 0;
    }
    int count = 0;
    while (count < num_process) {
        int found = 0;
        for (i = 0; i < num_process; i++) {
            if (!finish[i]) {
                int flag = 1;
                for (j = 0; j < num_resource; j++) {
                    if (need[i][j] > work[j]) {
                        flag = 0;
                        break;
                    }
                }
                if (flag) {
                    found = 1;
                    finish[i] = 1;
                    count++;
                    for (k = 0; k < num_resource; k++) {
                        work[k] += allocation[i][k];
                    }
                }
            }
        }
        if (!found) {
            return 0;
        }
    }
    return 1;
}

int request_check(int pid) {
    int i, j;
    for (i = 0; i < num_resource; i++) {
        if (request[i] > need[pid][i] || request[i] > available[i]) {
            return 0;
        }
    }
    for (i = 0; i < num_resource; i++) {
        available[i] -= request[i];
        allocation[pid][i] += request[i];
        need[pid][i] -= request[i];
    }
    if (safety_check()) {
        return 1;
    } else {
        for (i = 0; i < num_resource; i++) {
            available[i] += request[i];
            allocation[pid][i] -= request[i];
            need[pid][i] += request[i];
        }
        return 0;
    }
}

void request_resource() {
    int pid, i;
    printf("请输入请求资源的进程编号：\n");
    scanf("%d", &pid);
    printf("请输入请求的资源量：\n");
    for (i = 0; i < num_resource; i++) {
        scanf("%d", &request[i]);
    }
    if (request_check(pid)) {
        printf("请求成功！\n");
    } else {
        printf("请求失败！\n");
    }
}

int main() {
    init();
    if (safety_check()) {
        printf("系统安全！\n");
    } else {
        printf("系统不安全！\n");
        return 0;
    }
    while (1) {
        printf("请输入要进行的操作：\n");
        printf("1. 请求资源\n");
        printf("2. 退出\n");
        int op;
        scanf("%d", &op);
        if (op == 1) {
            request_resource();
        } else if (op == 2) {
            break;
        } else {
            printf("无效操作！\n");
        }
    }
    return 0;
}