磁盘调度算法c语言代码包括先来先服务（FCFS）、最短寻道时间优先（SSTF）、扫描算法（SCAN）

以下FCFS、SSTF和SCAN算法的C语言代码：

1. 先来先服务（FCFS）算法：

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

int main()
{
    int n, i, j, sum = 0, head, req[100];
    printf("Enter the number of requests: ");
    scanf("%d", &n);
    printf("Enter the requests: ");
    for(i=0; i<n; i++)
        scanf("%d", &req[i]);
    printf("Enter the initial head position: ");
    scanf("%d", &head);
    printf("The order of servicing the requests is:\n%d ", head);
    for(i=0; i<n; i++)
    {
        printf("%d ", req[i]);
        sum += abs(head - req[i]);
        head = req[i];
    }
    printf("\nTotal head movements: %d", sum);
    return 0;
}

2. 最短寻道时间优先（SSTF）算法：

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

int main()
{
    int n, i, j, sum = 0, head, min, diff, pos, req[100], flag[100]={0};
    printf("Enter the number of requests: ");
    scanf("%d", &n);
    printf("Enter the requests: ");
    for(i=0; i<n; i++)
        scanf("%d", &req[i]);
    printf("Enter the initial head position: ");
    scanf("%d", &head);
    printf("The order of servicing the requests is:\n%d ", head);
    for(i=0; i<n; i++)
    {
        min = 1000;
        for(j=0; j<n; j++)
        {
            if(flag[j]==0)
            {
                diff = abs(head - req[j]);
                if(diff < min)
                {
                    min = diff;
                    pos = j;
                }
            }
        }
        sum += abs(head - req[pos]);
        head = req[pos];
        flag[pos] = 1;
        printf("%d ", req[pos]);
    }
    printf("\nTotal head movements: %d", sum);
    return 0;
}

3. 扫描算法（SCAN）：

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

int main()
{
    int n, i, j, sum = 0, head, max, k, req[100], flag[100];
    printf("Enter the number of requests: ");
    scanf("%d", &n);
    printf("Enter the requests: ");
    for(i=0; i<n; i++)
        scanf("%d", &req[i]);
    printf("Enter the initial head position: ");
    scanf("%d", &head);
    printf("Enter the maximum cylinder size: ");
    scanf("%d", &max);
    printf("The order of servicing the requests is:\n");
    for(i=head; i<=max; i++)
        flag[i] = 0;
    for(i=0; i<n; i++)
        flag[req[i]] = 1;
    for(i=head; i>=0; i--)
        flag[i] = 0;
    sum = head;
    printf("%d ", head);
    for(i=head; i<=max; i++)
    {
        if(flag[i]==1)
        {
            printf("%d ", i);
            sum += abs(head - i);
            head = i;
        }
    }
    for(i=max; i>=0; i--)
    {
        if(flag[i]==1)
        {
            printf("%d ", i);
            sum += abs(head - i);
            head = i;
        }
    }
    printf("\nTotal head movements: %d", sum);
    return 0;
}

上述代码分别实现了FCFS、SSTF和SCAN三种磁盘调度算法，您可以根据需要选择其中的一种或多种进行使用。