一、课程设计目的 通过磁盘调度算法的模拟设计，了解磁盘调度的特点。 容 二、课程设计内容 模拟实现 FCFS、SSTF、电梯 LOOK、C-SCAN 算法，并计算及比较磁头移动道数。 示 三、要求及提示 本题目必须单人完成。 1、首先假设磁盘磁道数为 1500，磁头初始位置可任意设置。 2、用随机数生成函数产生“磁道号”序列（即磁盘请求的位置），共产生 400 个。其中 50%位于 0～499，25%分布在 500～999，25%分布在 1000～1499。具体的产生方法可参考 “题目一 页面置换算法的模拟实现及命中率对比”。 3、计算及比较每种磁盘调度算法下的磁头移动道数。 注：本题目要求给出图形可视化界面，并且能够动态模拟每个算法的调度过程，可采用 从上一个请求到下一个请求进行连线的方式。根据以上内容生成C语言程序

好的，以下是一个简单的C语言程序，实现了FCFS、SSTF、电梯LOOK、C-SCAN算法的模拟，并计算比较了磁头移动道数。同时，程序使用了图形库SDL，实现了图形可视化界面，能够动态模拟每个算法的调度过程。

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <SDL2/SDL.h>

#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#define RECT_WIDTH 10
#define RECT_HEIGHT 10
#define REQUEST_NUM 400
#define TRACK_NUM 1500

int requests[REQUEST_NUM];
int current_track = 0;
int direction = 1;
int fcfs_pos = 0;
int sstf_pos = 0;
int look_pos = 0;
int cscan_pos = 0;
int fcfs_track_moves = 0;
int sstf_track_moves = 0;
int look_track_moves = 0;
int cscan_track_moves = 0;

SDL_Window *window;
SDL_Renderer *renderer;

void init()
{
    srand(time(NULL));
    for (int i = 0; i < REQUEST_NUM; i++)
    {
        int r = rand() % 100;
        if (r < 50)
        {
            requests[i] = rand() % 500;
        }
        else if (r < 75)
        {
            requests[i] = 500 + rand() % 500;
        }
        else
        {
            requests[i] = 1000 + rand() % 500;
        }
    }

    if (SDL_Init(SDL_INIT_VIDEO) != 0)
    {
        printf("SDL_Init Error: %s\n", SDL_GetError());
        exit(1);
    }

    window = SDL_CreateWindow("Disk Scheduling", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
    if (window == NULL)
    {
        printf("SDL_CreateWindow Error: %s\n", SDL_GetError());
        exit(1);
    }

    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
    if (renderer == NULL)
    {
        printf("SDL_CreateRenderer Error: %s\n", SDL_GetError());
        exit(1);
    }
}

void close()
{
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();
}

void draw_rect(int x, int y)
{
    SDL_Rect rect = {x, y, RECT_WIDTH, RECT_HEIGHT};
    SDL_RenderFillRect(renderer, &rect);
}

void draw_line(int x1, int y1, int x2, int y2)
{
    SDL_RenderDrawLine(renderer, x1 + RECT_WIDTH / 2, y1 + RECT_HEIGHT / 2, x2 + RECT_WIDTH / 2, y2 + RECT_HEIGHT / 2);
}

void fcfs()
{
    for (int i = 0; i < REQUEST_NUM; i++)
    {
        fcfs_track_moves += abs(requests[i] - fcfs_pos);
        draw_line(fcfs_pos * RECT_WIDTH, 0, requests[i] * RECT_WIDTH, RECT_HEIGHT);
        fcfs_pos = requests[i];
    }
}

int find_nearest_request(int pos, int *visited)
{
    int min_distance = TRACK_NUM;
    int nearest_index = -1;
    for (int i = 0; i < REQUEST_NUM; i++)
    {
        if (!visited[i])
        {
            int distance = abs(requests[i] - pos);
            if (distance < min_distance)
            {
                min_distance = distance;
                nearest_index = i;
            }
        }
    }
    return nearest_index;
}

void sstf()
{
    int visited[REQUEST_NUM] = {0};
    for (int i = 0; i < REQUEST_NUM; i++)
    {
        int nearest_index = find_nearest_request(sstf_pos, visited);
        visited[nearest_index] = 1;
        sstf_track_moves += abs(requests[nearest_index] - sstf_pos);
        draw_line(sstf_pos * RECT_WIDTH, 2 * RECT_HEIGHT, requests[nearest_index] * RECT_WIDTH, 3 * RECT_HEIGHT);
        sstf_pos = requests[nearest_index];
    }
}

void look()
{
    while (1)
    {
        int nearest_index = find_nearest_request(look_pos, NULL);
        if (nearest_index == -1)
        {
            break;
        }
        look_track_moves += abs(requests[nearest_index] - look_pos);
        draw_line(look_pos * RECT_WIDTH, 4 * RECT_HEIGHT, requests[nearest_index] * RECT_WIDTH, 5 * RECT_HEIGHT);
        look_pos = requests[nearest_index];
    }
}

void cscan()
{
    int visited[REQUEST_NUM] = {0};
    while (1)
    {
        int nearest_index = -1;
        if (direction == 1)
        {
            nearest_index = find_nearest_request(cscan_pos, visited);
            if (nearest_index == -1)
            {
                direction = -1;
                continue;
            }
            if (requests[nearest_index] > cscan_pos && cscan_pos != 0)
            {
                draw_line(cscan_pos * RECT_WIDTH, 6 * RECT_HEIGHT, 0, 7 * RECT_HEIGHT);
                cscan_track_moves += cscan_pos;
                cscan_pos = 0;
                draw_line(0, 7 * RECT_HEIGHT, requests[nearest_index] * RECT_WIDTH, 7 * RECT_HEIGHT);
            }
            else
            {
                draw_line(cscan_pos * RECT_WIDTH, 6 * RECT_HEIGHT, requests[nearest_index] * RECT_WIDTH, 7 * RECT_HEIGHT);
            }
            cscan_track_moves += abs(requests[nearest_index] - cscan_pos);
            cscan_pos = requests[nearest_index];
            visited[nearest_index] = 1;
        }
        else
        {
            nearest_index = find_nearest_request(cscan_pos, visited);
            if (nearest_index == -1)
            {
                break;
            }
            if (requests[nearest_index] < cscan_pos && cscan_pos != TRACK_NUM - 1)
            {
                draw_line(cscan_pos * RECT_WIDTH, 6 * RECT_HEIGHT, (TRACK_NUM - 1) * RECT_WIDTH, 7 * RECT_HEIGHT);
                cscan_track_moves += TRACK_NUM - 1 - cscan_pos;
                cscan_pos = TRACK_NUM - 1;
                draw_line((TRACK_NUM - 1) * RECT_WIDTH, 7 * RECT_HEIGHT, requests[nearest_index] * RECT_WIDTH, 7 * RECT_HEIGHT);
            }
            else
            {
                draw_line(cscan_pos * RECT_WIDTH, 6 * RECT_HEIGHT, requests[nearest_index] * RECT_WIDTH, 7 * RECT_HEIGHT);
            }
            cscan_track_moves += abs(requests[nearest_index] - cscan_pos);
            cscan_pos = requests[nearest_index];
            visited[nearest_index] = 1;
        }
    }
}

int main(int argc, char *argv[])
{
    init();

    SDL_Event event;
    int quit = 0;

    while (!quit)
    {
        while (SDL_PollEvent(&event))
        {
            if (event.type == SDL_QUIT)
            {
                quit = 1;
            }
        }

        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
        SDL_RenderClear(renderer);

        SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
        fcfs();

        SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255);
        sstf();

        SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255);
        look();

        SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255);
        cscan();

        SDL_RenderPresent(renderer);
    }

    printf("FCFS track moves: %d\n", fcfs_track_moves);
    printf("SSTF track moves: %d\n", sstf_track_moves);
    printf("LOOK track moves: %d\n", look_track_moves);
    printf("C-SCAN track moves: %d\n", cscan_track_moves);

    close();
    return 0;
}

需要注意的是，这只是一个简单的程序示例，可能还有一些细节需要完善，比如错误处理、内存管理等。同时，程序还可以优化，比如可以使用更高效的数据结构来加速查找最近的磁盘请求。