通过设计程序，实现磁盘寻道算法中FCFS、SSTF、SCAN和CSCAN四种算法C++

好的，以下是四种磁盘寻道算法的C++程序实现。

1. 先来先服务算法（FCFS）

#include <iostream>
#include <cmath>
using namespace std;

int FCFS(int disk_queue[], int size, int start_pos) {
    int total_distance = 0;
    int current_pos = start_pos;
    for (int i = 0; i < size; i++) {
        int distance = abs(disk_queue[i] - current_pos);
        total_distance += distance;
        current_pos = disk_queue[i];
    }
    return total_distance;
}

int main() {
    int disk_queue[] = {98, 183, 37, 122, 14, 124, 65, 67};
    int size = sizeof(disk_queue) / sizeof(disk_queue[0]);
    int start_pos = 53;
    int total_distance = FCFS(disk_queue, size, start_pos);
    cout << "FCFS: " << total_distance << endl;
    return 0;
}

2. 最短寻道时间优先算法（SSTF）

#include <iostream>
#include <cmath>
using namespace std;

int SSTF(int disk_queue[], int size, int start_pos) {
    int total_distance = 0;
    int current_pos = start_pos;
    while (size > 0) {
        int min_distance = INT_MAX;
        int next_pos = 0;
        for (int i = 0; i < size; i++) {
            int distance = abs(disk_queue[i] - current_pos);
            if (distance < min_distance) {
                min_distance = distance;
                next_pos = i;
            }
        }
        total_distance += min_distance;
        current_pos = disk_queue[next_pos];
        for (int i = next_pos; i < size - 1; i++) {
            disk_queue[i] = disk_queue[i+1];
        }
        size--;
    }
    return total_distance;
}

int main() {
    int disk_queue[] = {98, 183, 37, 122, 14, 124, 65, 67};
    int size = sizeof(disk_queue) / sizeof(disk_queue[0]);
    int start_pos = 53;
    int total_distance = SSTF(disk_queue, size, start_pos);
    cout << "SSTF: " << total_distance << endl;
    return 0;
}

3. 扫描算法（SCAN）

#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;

int SCAN(int disk_queue[], int size, int start_pos) {
    int total_distance = 0;
    int current_pos = start_pos;
    sort(disk_queue, disk_queue + size);
    int index = 0;
    for (int i = 0; i < size; i++) {
        if (disk_queue[i] > start_pos) {
            index = i;
            break;
        }
    }
    bool direction = true;
    while (index >= 0 && index < size) {
        if (direction) {
            total_distance += abs(disk_queue[index] - current_pos);
            current_pos = disk_queue[index];
            index++;
            if (index == size) {
                total_distance += abs(current_pos - 199);
                current_pos = 199;
                direction = false;
                index--;
            }
        } else {
            total_distance += abs(disk_queue[index] - current_pos);
            current_pos = disk_queue[index];
            index--;
            if (index < 0) {
                total_distance += abs(current_pos - 0);
                current_pos = 0;
                direction = true;
                index = 0;
            }
        }
    }
    return total_distance;
}

int main() {
    int disk_queue[] = {98, 183, 37, 122, 14, 124, 65, 67};
    int size = sizeof(disk_queue) / sizeof(disk_queue[0]);
    int start_pos = 53;
    int total_distance = SCAN(disk_queue, size, start_pos);
    cout << "SCAN: " << total_distance << endl;
    return 0;
}

4. 循环扫描算法（CSCAN）

#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;

int CSCAN(int disk_queue[], int size, int start_pos) {
    int total_distance = 0;
    int current_pos = start_pos;
    sort(disk_queue, disk_queue + size);
    int index = 0;
    for (int i = 0; i < size; i++) {
        if (disk_queue[i] > start_pos) {
            index = i;
            break;
        }
    }
    bool direction = true;
    while (index >= 0 && index < size) {
        if (direction) {
            total_distance += abs(disk_queue[index] - current_pos);
            current_pos = disk_queue[index];
            index++;
            if (index == size) {
                total_distance += abs(current_pos - 199);
                current_pos = 199;
                direction = false;
                index = 0;
            }
        } else {
            total_distance += abs(disk_queue[index] - current_pos);
            current_pos = disk_queue[index];
            index--;
            if (index < 0) {
                total_distance += abs(current_pos - 0);
                current_pos = 0;
                direction = true;
                index = 0;
            }
        }
    }
    return total_distance;
}

int main() {
    int disk_queue[] = {98, 183, 37, 122, 14, 124, 65, 67};
    int size = sizeof(disk_queue) / sizeof(disk_queue[0]);
    int start_pos = 53;
    int total_distance = CSCAN(disk_queue, size, start_pos);
    cout << "CSCAN: " << total_distance << endl;
    return 0;
}

以上四种磁盘寻道算法的程序实现均为C++语言。