详细代码实现

好的，以下是详细的 C++ 代码实现：

#include <iostream>
#include <algorithm>
#include <vector>
#include <cstdlib>
#include <ctime>

using namespace std;

const int CYLINDERS = 5000;
const int REQUESTS = 1000;

//FCFS磁盘调度算法
int fcfs(int initialPosition, const vector<int>& requests) {
    int totalMovement = 0;
    int currentPosition = initialPosition;

    for (int i = 0; i < REQUESTS; ++i) {
        totalMovement += abs(requests[i] - currentPosition);
        currentPosition = requests[i];
    }

    return totalMovement;
}

//SSTF磁盘调度算法
int sstf(int initialPosition, const vector<int>& requests) {
    int totalMovement = 0;
    int currentPosition = initialPosition;
    vector<int> remainingRequests(requests.begin(), requests.end());

    for (int i = 0; i < REQUESTS; ++i) {
        //找到距离当前位置最近的请求
        int nextRequest = *min_element(remainingRequests.begin(), remainingRequests.end(),
            [=](int a, int b) { return abs(a - currentPosition) < abs(b - currentPosition); });

        totalMovement += abs(nextRequest - currentPosition);
        currentPosition = nextRequest;

        //从剩余请求中移除当前请求
        remainingRequests.erase(find(remainingRequests.begin(), remainingRequests.end(), nextRequest));
    }

    return totalMovement;
}

//SCAN磁盘调度算法
int scan(int initialPosition, const vector<int>& requests) {
    int totalMovement = 0;
    int currentPosition = initialPosition;
    vector<int> remainingRequests(requests.begin(), requests.end());

    //按请求顺序排序
    sort(remainingRequests.begin(), remainingRequests.end());

    //找到初始位置的索引
    auto initialPositionIterator = find(remainingRequests.begin(), remainingRequests.end(), initialPosition);
    int initialPositionIndex = distance(remainingRequests.begin(), initialPositionIterator);

    //处理初始位置两边的请求
    vector<int> leftRequests(remainingRequests.begin(), initialPositionIterator);
    vector<int> rightRequests(initialPositionIterator + 1, remainingRequests.end());

    //先处理往右扫描的请求
    for (int i = initialPositionIndex; i < REQUESTS; ++i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];
    }

    //再处理往左扫描的请求
    for (int i = initialPositionIndex - 1; i >= 0; --i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];
    }

    return totalMovement;
}

//C-SCAN磁盘调度算法
int cscan(int initialPosition, const vector<int>& requests) {
    int totalMovement = 0;
    int currentPosition = initialPosition;
    vector<int> remainingRequests(requests.begin(), requests.end());

    //按请求顺序排序
    sort(remainingRequests.begin(), remainingRequests.end());

    //找到初始位置的索引
    auto initialPositionIterator = find(remainingRequests.begin(), remainingRequests.end(), initialPosition);
    int initialPositionIndex = distance(remainingRequests.begin(), initialPositionIterator);

    //处理初始位置两边的请求
    vector<int> leftRequests(remainingRequests.begin(), initialPositionIterator);
    vector<int> rightRequests(initialPositionIterator + 1, remainingRequests.end());

    //先处理往右扫描的请求
    for (int i = initialPositionIndex; i < REQUESTS; ++i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];
    }

    //处理最右侧的请求
    totalMovement += (CYLINDERS - 1 - currentPosition);

    //再处理往左扫描的请求
    currentPosition = 0;
    for (int i = 0; i < initialPositionIndex; ++i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];
    }

    return totalMovement;
}

//LOOK磁盘调度算法
int look(int initialPosition, const vector<int>& requests) {
    int totalMovement = 0;
    int currentPosition = initialPosition;
    vector<int> remainingRequests(requests.begin(), requests.end());

    //按请求顺序排序
    sort(remainingRequests.begin(), remainingRequests.end());

    //找到初始位置的索引
    auto initialPositionIterator = find(remainingRequests.begin(), remainingRequests.end(), initialPosition);
    int initialPositionIndex = distance(remainingRequests.begin(), initialPositionIterator);

    //处理初始位置两边的请求
    vector<int> leftRequests(remainingRequests.begin(), initialPositionIterator);
    vector<int> rightRequests(initialPositionIterator + 1, remainingRequests.end());

    //先处理往右扫描的请求
    for (int i = initialPositionIndex; i < REQUESTS; ++i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];

        //如果已经处理完所有请求，或者当前请求是最后一个请求，就跳出循环
        if ((i == REQUESTS - 1) || (remainingRequests[i + 1] > currentPosition)) {
            break;
        }
    }

    //再处理往左扫描的请求
    for (int i = initialPositionIndex - 1; i >= 0; --i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];

        //如果已经处理完所有请求，或者当前请求是第一个请求，就跳出循环
        if ((i == 0) || (remainingRequests[i - 1] < currentPosition)) {
            break;
        }
    }

    return totalMovement;
}

//C-LOOK磁盘调度算法
int clook(int initialPosition, const vector<int>& requests) {
    int totalMovement = 0;
    int currentPosition = initialPosition;
    vector<int> remainingRequests(requests.begin(), requests.end());

    //按请求顺序排序
    sort(remainingRequests.begin(), remainingRequests.end());

    //找到初始位置的索引
    auto initialPositionIterator = find(remainingRequests.begin(), remainingRequests.end(), initialPosition);
    int initialPositionIndex = distance(remainingRequests.begin(), initialPositionIterator);

    //处理初始位置两边的请求
    vector<int> leftRequests(remainingRequests.begin(), initialPositionIterator);
    vector<int> rightRequests(initialPositionIterator + 1, remainingRequests.end());

    //先处理往右扫描的请求
    for (int i = initialPositionIndex; i < REQUESTS; ++i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];

        //如果已经处理完所有请求，或者当前请求是最后一个请求，就跳出循环
        if ((i == REQUESTS - 1) || (remainingRequests[i + 1] > currentPosition)) {
            break;
        }
    }

    //再处理往左扫描的请求
    for (int i = 0; i < initialPositionIndex; ++i) {
        totalMovement += abs(remainingRequests[i] - currentPosition);
        currentPosition = remainingRequests[i];

        //如果已经处理完所有请求，或者当前请求是最后一个请求，就跳出循环
        if ((i == initialPositionIndex - 1) || (remainingRequests[i + 1] > currentPosition)) {
            break;
        }
    }

    return totalMovement;
}

int main(int argc, char** argv) {
    if (argc != 2) {
        cout << "Usage: " << argv[0] << " initialPosition\n";
        return 1;
    }

    //解析命令行参数
    int initialPosition = atoi(argv[1]);

    //生成随机请求序列
    srand(time(nullptr));
    vector<int> requests(REQUESTS);
    for (int i = 0; i < REQUESTS; ++i) {
        requests[i] = rand() % CYLINDERS;
    }

    cout << "FCFS: " << fcfs(initialPosition, requests) << "\n";
    cout << "SSTF: " << sstf(initialPosition, requests) << "\n";
    cout << "SCAN: " << scan(initialPosition, requests) << "\n";
    cout << "C-SCAN: " << cscan(initialPosition, requests) << "\n";
    cout << "LOOK: " << look(initialPosition, requests) << "\n";
    cout << "C-LOOK: " << clook(initialPosition, requests) << "\n";

    return 0;
}

代码中实现了六种磁盘调度算法：FCFS、SSTF、SCAN、C-SCAN、LOOK 和 C-LOOK。程序首先解析了命令行参数，然后生成了一个随机的请求序列。接着，程序依次调用每个算法，并输出每个算法需要移动的磁头总距离。