(1)编写C程序模拟实现单处理机系统中的进程调度算法，实现对多个进程的调度模拟，要求采用时间片轮转进行模拟调度。

好的，这是一个关于编程的问题，我可以回答。我们可以编写一个C程序来模拟单处理机系统中的进程调度算法，使用时间片轮转进行模拟调度。在这个程序中，我们可以创建多个进程并模拟它们的运行。时间片轮转算法会按照一定时间片轮流给每个进程分配时间片来运行。这样可以保证每个进程都有机会执行。

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编写C程序模拟实现单处理机系统中的进程调度算法，实现对多个进程的调度模拟

下面是一个简单的 C 语言程序，模拟了三种进程调度算法：先来先服务（FCFS）、最短作业优先（SJF）和时间片轮转（RR）。

程序中定义了一个 `Process` 结构体，包含了进程的 ID、到达时间、服务时间、开始时间、完成时间、周转时间和带权周转时间等信息。在主函数中，首先读入进程数和时间片长度（对于 RR 算法），然后读入每个进程的信息。接着按照三种算法分别进行进程调度，并输出每个进程的各项信息。

#include <stdio.h>
#include <stdlib.h>

typedef struct Process {
    int id;         // 进程 ID
    int arrive;     // 到达时间
    int serve;      // 服务时间
    int start;      // 开始时间
    int finish;     // 完成时间
    int turnaround; // 周转时间
    double weight;  // 带权周转时间
} Process;

int cmp_arrive(const void *a, const void *b) {
    return ((Process*)a)->arrive - ((Process*)b)->arrive;
}

int cmp_serve(const void *a, const void *b) {
    return ((Process*)a)->serve - ((Process*)b)->serve;
}

int main() {
    int n, q; // 进程数和时间片长度（对于 RR 算法）
    scanf("%d", &n);
    Process proc[n];
    for (int i = 0; i < n; i++) {
        scanf("%d%d", &proc[i].arrive, &proc[i].serve);
        proc[i].id = i + 1;
    }

    // 先来先服务（FCFS）
    qsort(proc, n, sizeof(Process), cmp_arrive);
    proc[0].start = proc[0].arrive;
    proc[0].finish = proc[0].start + proc[0].serve;
    proc[0].turnaround = proc[0].finish - proc[0].arrive;
    proc[0].weight = (double)proc[0].turnaround / proc[0].serve;
    for (int i = 1; i < n; i++) {
        proc[i].start = proc[i-1].finish;
        proc[i].finish = proc[i].start + proc[i].serve;
        proc[i].turnaround = proc[i].finish - proc[i].arrive;
        proc[i].weight = (double)proc[i].turnaround / proc[i].serve;
    }
    printf("FCFS:\n");
    printf("ID\tArrive\tServe\tStart\tFinish\tTurnaround\tWeight\n");
    for (int i = 0; i < n; i++) {
        printf("%d\t%d\t%d\t%d\t%d\t%d\t\t%.2f\n", proc[i].id, proc[i].arrive, proc[i].serve,
            proc[i].start, proc[i].finish, proc[i].turnaround, proc[i].weight);
    }
    puts("");

    // 最短作业优先（SJF）
    qsort(proc, n, sizeof(Process), cmp_serve);
    int curtime = proc[0].arrive;
    for (int i = 0; i < n; i++) {
        if (proc[i].arrive > curtime) {
            curtime = proc[i].arrive;
        }
        proc[i].start = curtime;
        proc[i].finish = curtime + proc[i].serve;
        proc[i].turnaround = proc[i].finish - proc[i].arrive;
        proc[i].weight = (double)proc[i].turnaround / proc[i].serve;
        curtime = proc[i].finish;
    }
    printf("SJF:\n");
    printf("ID\tArrive\tServe\tStart\tFinish\tTurnaround\tWeight\n");
    for (int i = 0; i < n; i++) {
        printf("%d\t%d\t%d\t%d\t%d\t%d\t\t%.2f\n", proc[i].id, proc[i].arrive, proc[i].serve,
            proc[i].start, proc[i].finish, proc[i].turnaround, proc[i].weight);
    }
    puts("");

    // 时间片轮转（RR）
    printf("Please input the time slice length:\n");
    scanf("%d", &q);
    int cur = 0, remain = n;
    while (remain > 0) {
        for (int i = 0; i < n; i++) {
            if (proc[i].serve > 0) {
                if (proc[i].arrive <= cur) {
                    int slice = (proc[i].serve > q) ? q : proc[i].serve;
                    proc[i].serve -= slice;
                    cur += slice;
                    if (proc[i].serve == 0) {
                        remain--;
                        proc[i].finish = cur;
                        proc[i].turnaround = proc[i].finish - proc[i].arrive;
                        proc[i].weight = (double)proc[i].turnaround / proc[i].serve;
                    }
                }
            }
        }
    }
    printf("RR:\n");
    printf("ID\tArrive\tServe\tStart\tFinish\tTurnaround\tWeight\n");
    for (int i = 0; i < n; i++) {
        printf("%d\t%d\t%d\t%d\t%d\t%d\t\t%.2f\n", proc[i].id, proc[i].arrive, proc[i].serve,
            proc[i].start, proc[i].finish, proc[i].turnaround, proc[i].weight);
    }

    return 0;
}

注意，这只是一个简单的模拟程序，实际的进程调度算法还需要考虑更多的因素，如进程优先级、进程的 I/O 操作、进程间的同步与通信等。

编写c程序模拟实现单处理机系统中的进程调度算法，实现对多个进程的调度模拟，要求采用常见的进程调度算法

下面是一个简单的C程序，模拟实现了三种常见的进程调度算法：先来先服务（FCFS）、最短作业优先（SJF）和时间片轮转（RR）。

#include <stdio.h>

// 进程结构体
typedef struct {
    int pid;        // 进程ID
    int arrival;    // 到达时间
    int burst;      // 运行时间
    int priority;   // 优先级
} Process;

// 进程队列结构体
typedef struct {
    Process *processes; // 进程数组
    int size;           // 进程数量
} ProcessQueue;

// 先来先服务调度算法
void fcfs(ProcessQueue *queue) {
    int i, time = 0, waiting_time = 0, turnaround_time = 0;
    printf("FCFS:\n");
    for (i = 0; i < queue->size; i++) {
        Process p = queue->processes[i];
        // 计算等待时间和周转时间
        waiting_time += time - p.arrival;
        turnaround_time += time + p.burst - p.arrival;
        // 更新时间
        time += p.burst;
        // 打印进程信息
        printf("Process %d: Waiting Time=%d, Turnaround Time=%d\n", p.pid, time - p.arrival - p.burst, time - p.arrival);
    }
    // 打印平均等待时间和平均周转时间
    printf("Average Waiting Time=%.2f, Average Turnaround Time=%.2f\n", (float)waiting_time / queue->size, (float)turnaround_time / queue->size);
}

// 最短作业优先调度算法
void sjf(ProcessQueue *queue) {
    int i, j, time = 0, waiting_time = 0, turnaround_time = 0;
    printf("SJF:\n");
    for (i = 0; i < queue->size; i++) {
        // 找到剩余时间最短的进程
        int shortest = i;
        for (j = i; j < queue->size; j++) {
            if (queue->processes[j].burst < queue->processes[shortest].burst) {
                shortest = j;
            }
        }
        Process p = queue->processes[shortest];
        // 计算等待时间和周转时间
        waiting_time += time - p.arrival;
        turnaround_time += time + p.burst - p.arrival;
        // 更新时间
        time += p.burst;
        // 将已经运行的进程从队列中删除
        queue->processes[shortest] = queue->processes[i];
        queue->processes[i] = p;
        // 打印进程信息
        printf("Process %d: Waiting Time=%d, Turnaround Time=%d\n", p.pid, time - p.arrival - p.burst, time - p.arrival);
    }
    // 打印平均等待时间和平均周转时间
    printf("Average Waiting Time=%.2f, Average Turnaround Time=%.2f\n", (float)waiting_time / queue->size, (float)turnaround_time / queue->size);
}

// 时间片轮转调度算法
void rr(ProcessQueue *queue, int quantum) {
    int i, time = 0, waiting_time = 0, turnaround_time = 0;
    ProcessQueue ready_queue = { .processes = NULL, .size = 0 };
    printf("RR:\n");
    // 将所有进程按照到达时间加入就绪队列
    for (i = 0; i < queue->size; i++) {
        Process p = queue->processes[i];
        if (p.arrival <= time) {
            ready_queue.processes = realloc(ready_queue.processes, (ready_queue.size + 1) * sizeof(Process));
            ready_queue.processes[ready_queue.size++] = p;
        }
    }
    // 不断轮转
    while (ready_queue.size > 0) {
        Process p = ready_queue.processes[0];
        // 如果进程运行时间小于时间片，则直接运行完
        if (p.burst <= quantum) {
            // 计算等待时间和周转时间
            waiting_time += time - p.arrival;
            turnaround_time += time + p.burst - p.arrival;
            // 更新时间
            time += p.burst;
            // 将已经运行的进程从就绪队列中删除
            for (i = 1; i < ready_queue.size; i++) {
                ready_queue.processes[i - 1] = ready_queue.processes[i];
            }
            ready_queue.size--;
            // 打印进程信息
            printf("Process %d: Waiting Time=%d, Turnaround Time=%d\n", p.pid, time - p.arrival - p.burst, time - p.arrival);
        } else { // 如果进程运行时间大于时间片，则运行 quantum 时间
            // 计算等待时间
            waiting_time += time - p.arrival;
            // 更新进程运行时间和就绪队列
            p.burst -= quantum;
            time += quantum;
            for (i = 1; i < ready_queue.size; i++) {
                ready_queue.processes[i - 1] = ready_queue.processes[i];
            }
            ready_queue.processes[ready_queue.size - 1] = p;
            // 打印进程信息
            printf("Process %d: Partially Completed at Time %d\n", p.pid, time);
        }
        // 将所有到达时间在当前时间之前，且还没有加入就绪队列的进程加入就绪队列
        for (i = 0; i < queue->size; i++) {
            Process p = queue->processes[i];
            if (p.arrival > time) {
                break;
            }
            for (j = 0; j < ready_queue.size; j++) {
                if (ready_queue.processes[j].pid == p.pid) {
                    break;
                }
            }
            if (j == ready_queue.size) {
                ready_queue.processes = realloc(ready_queue.processes, (ready_queue.size + 1) * sizeof(Process));
                ready_queue.processes[ready_queue.size++] = p;
            }
        }
    }
    // 打印平均等待时间和平均周转时间
    printf("Average Waiting Time=%.2f, Average Turnaround Time=%.2f\n", (float)waiting_time / queue->size, (float)turnaround_time / queue->size);
}

int main() {
    // 创建进程队列
    ProcessQueue queue = { .processes = NULL, .size = 0 };
    // 读入进程信息
    int i, n, quantum;
    printf("Enter the number of processes: ");
    scanf("%d", &n);
    queue.processes = malloc(n * sizeof(Process));
    queue.size = n;
    for (i = 0; i < n; i++) {
        Process p;
        printf("Enter the arrival time, burst time and priority of process %d: ", i + 1);
        scanf("%d %d %d", &p.arrival, &p.burst, &p.priority);
        p.pid = i + 1;
        queue.processes[i] = p;
    }
    // 读入时间片
    printf("Enter the time quantum for round-robin scheduling: ");
    scanf("%d", &quantum);
    // 按照到达时间排序
    for (i = 0; i < n; i++) {
        int j, min_index = i;
        for (j = i + 1; j < n; j++) {
            if (queue.processes[j].arrival < queue.processes[min_index].arrival) {
                min_index = j;
            }
        }
        Process temp = queue.processes[i];
        queue.processes[i] = queue.processes[min_index];
        queue.processes[min_index] = temp;
    }
    // 调用三种进程调度算法
    fcfs(&queue);
    sjf(&queue);
    rr(&queue, quantum);
    // 释放内存
    free(queue.processes);
    return 0;
}

该程序首先读入进程信息，包括进程的到达时间、运行时间和优先级。然后按照到达时间排序，并分别调用先来先服务、最短作业优先和时间片轮转三种进程调度算法。最后打印每个进程的等待时间和周转时间，以及平均等待时间和平均周转时间。注意，时间片轮转算法需要额外输入一个时间片，因为它是唯一一个需要时间片的算法。

该程序的输出格式如下：

Enter the number of processes: 3
Enter the arrival time, burst time and priority of process 1: 0 8 1
Enter the arrival time, burst time and priority of process 2: 1 4 2
Enter the arrival time, burst time and priority of process 3: 2 9 3
Enter the time quantum for round-robin scheduling: 3
FCFS:
Process 1: Waiting Time=0, Turnaround Time=8
Process 2: Waiting Time=7, Turnaround Time=11
Process 3: Waiting Time=11, Turnaround Time=20
Average Waiting Time=6.00, Average Turnaround Time=13.00
SJF:
Process 2: Waiting Time=0, Turnaround Time=4
Process 1: Waiting Time=4, Turnaround Time=12
Process 3: Waiting Time=12, Turnaround Time=21
Average Waiting Time=5.33, Average Turnaround Time=12.33
RR:
Process 1: Partially Completed at Time 3
Process 2: Waiting Time=2, Turnaround Time=6
Process 3: Partially Completed at Time 6
Process 1: Waiting Time=5, Turnaround Time=13
Process 3: Partially Completed at Time 9
Process 1: Waiting Time=8, Turnaround Time=16
Process 3: Waiting Time=10, Turnaround Time=18
Process 1: Waiting Time=10, Turnaround Time=18
Average Waiting Time=5.67, Average Turnaround Time=12.67