1、设计进程控制块 PCB 表结构。 2. 输入一组进程及其相关参数（包括进程名、序号、所需服务时间、优先级等）。 3. 采用至少三种调度算法，可选调度算法有上述 6 种。 4. 计算出这组进程的平均周转时间、响应时间及带权周转时间。 c语言实现

好的，我明白了您的问题。以下是我的回答：

1. 进程控制块 PCB 表结构：

struct process {
    char name[20];  // 进程名
    int id;  // 进程序号
    int service_time;  // 所需服务时间
    int priority;  // 进程优先级
    int start_time;  // 进程开始时间
    int end_time;  // 进程结束时间
    int wait_time;  // 进程等待时间
    int turnaround_time;  // 进程周转时间
    float weighted_turnaround_time;  // 进程带权周转时间
};

2. 输入一组进程及其相关参数：

struct process processes[] = {
    {"P1", 1, 5, 3},
    {"P2", 2, 2, 2},
    {"P3", 3, 4, 1},
    {"P4", 4, 1, 4},
    {"P5", 5, 6, 5}
};
int num_processes = sizeof(processes) / sizeof(processes[0]);

3. 调度算法实现：

先定义一些辅助函数：

// 按照进程优先级从高到低排序
void sort_by_priority(struct process *processes, int num_processes) {
    for (int i = 0; i < num_processes - 1; i++) {
        for (int j = i + 1; j < num_processes; j++) {
            if (processes[i].priority < processes[j].priority) {
                struct process temp = processes[i];
                processes[i] = processes[j];
                processes[j] = temp;
            }
        }
    }
}

// 按照进程服务时间从短到长排序
void sort_by_service_time(struct process *processes, int num_processes) {
    for (int i = 0; i < num_processes - 1; i++) {
        for (int j = i + 1; j < num_processes; j++) {
            if (processes[i].service_time > processes[j].service_time) {
                struct process temp = processes[i];
                processes[i] = processes[j];
                processes[j] = temp;
            }
        }
    }
}

// 计算进程等待时间、周转时间和带权周转时间
void calculate_times(struct process *processes, int num_processes) {
    int current_time = 0;
    for (int i = 0; i < num_processes; i++) {
        processes[i].start_time = current_time;
        processes[i].wait_time = current_time;
        current_time += processes[i].service_time;
        processes[i].end_time = current_time;
        processes[i].turnaround_time = processes[i].end_time - processes[i].start_time;
        processes[i].weighted_turnaround_time = (float) processes[i].turnaround_time / processes[i].service_time;
    }
}

然后分别实现三种调度算法：

先来看先来先服务（FCFS）：

void fcfs(struct process *processes, int num_processes) {
    printf("FCFS:\n");
    sort_by_service_time(processes, num_processes);
    calculate_times(processes, num_processes);
    for (int i = 0; i < num_processes; i++) {
        printf("%s:\n", processes[i].name);
        printf("start_time: %d, end_time: %d, wait_time: %d, turnaround_time: %d, weighted_turnaround_time: %f\n",
            processes[i].start_time, processes[i].end_time, processes[i].wait_time, processes[i].turnaround_time, processes[i].weighted_turnaround_time);
    }
}

最短作业优先（SJF）：

void sjf(struct process *processes, int num_processes) {
    printf("SJF:\n");
    sort_by_service_time(processes, num_processes);
    calculate_times(processes, num_processes);
    for (int i = 0; i < num_processes; i++) {
        printf("%s:\n", processes[i].name);
        printf("start_time: %d, end_time: %d, wait_time: %d, turnaround_time: %d, weighted_turnaround_time: %f\n",
            processes[i].start_time, processes[i].end_time, processes[i].wait_time, processes[i].turnaround_time, processes[i].weighted_turnaround_time);
    }
}

优先级调度：

void priority(struct process *processes, int num_processes) {
    printf("Priority:\n");
    sort_by_priority(processes, num_processes);
    calculate_times(processes, num_processes);
    for (int i = 0; i < num_processes; i++) {
        printf("%s:\n", processes[i].name);
        printf("start_time: %d, end_time: %d, wait_time: %d, turnaround_time: %d, weighted_turnaround_time: %f\n",
            processes[i].start_time, processes[i].end_time, processes[i].wait_time, processes[i].turnaround_time, processes[i].weighted_turnaround_time);
    }
}

4. 计算出这组进程的平均周转时间、响应时间及带权周转时间：

int total_turnaround_time = 0;
int total_wait_time = 0;
float total_weighted_turnaround_time = 0;
for (int i = 0; i < num_processes; i++) {
    total_turnaround_time += processes[i].turnaround_time;
    total_wait_time += processes[i].wait_time;
    total_weighted_turnaround_time += processes[i].weighted_turnaround_time;
}
float avg_turnaround_time = (float) total_turnaround_time / num_processes;
float avg_wait_time = (float) total_wait_time / num_processes;
float avg_weighted_turnaround_time = total_weighted_turnaround_time / num_processes;

printf("Average turnaround time: %f\n", avg_turnaround_time);
printf("Average wait time: %f\n", avg_wait_time);
printf("Average weighted turnaround time: %f\n", avg_weighted_turnaround_time);

完整代码如下：