磁盘调度算法比较差异的c语言算法

好的，下面是五种磁盘调度算法的C语言代码实现和对比：

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

void FCFS(int queue[], int head, int n)
{
    int seek = 0;
    int cur_track;
    for (int i = 0; i < n; i++) {
        cur_track = queue[i];
        seek += abs(cur_track - head);
        head = cur_track;
    }
    printf("FCFS algorithm: Total seek time = %d\n", seek);
}

void SSTF(int queue[], int head, int n)
{
    int seek = 0, min, pos;
    int cur_track = head;

    for (int i = 0; i < n; i++) {
        min = INT_MAX;
        for (int j = 0; j < n; j++) {
            if (abs(queue[j] - cur_track) < min) {
                pos = j;
                min = abs(queue[j] - cur_track);
            }
        }
        seek += min;
        cur_track = queue[pos];
        queue[pos] = INT_MAX;
    }
    printf("SSTF algorithm: Total seek time = %d\n", seek);
}

void SCAN(int queue[], int head, int n)
{
    int seek = 0;
    int cur_track;
    int max_track = queue[n - 1];

    for (int i = 0; i < n; i++) {
        if (head < queue[i])
            break;
        seek += abs(head - queue[i]);
        head = queue[i];
    }
    seek += abs(head - 0);
    head = 0;
    for (int i = 0; i < n; i++) {
        if (head < queue[i] && queue[i] <= max_track) {
            seek += abs(head - queue[i]);
            head = queue[i];
        }
    }
    printf("SCAN algorithm: Total seek time = %d\n", seek);
}

void CSCAN(int queue[], int head, int n)
{
    int seek = 0;
    int cur_track;
    int max_track = queue[n - 1];

    for (int i = 0; i < n; i++) {
        if (head < queue[i])
            break;
        seek += abs(head - queue[i]);
        head = queue[i];
    }
    seek += abs(head - 0);
    head = 0;
    for (int i = 0; i < n; i++) {
        if (head < queue[i] && queue[i] <= max_track) {
            seek += abs(head - queue[i]);
            head = queue[i];
        }
    }
    seek += abs(head - max_track);
    head = max_track;
    for (int i = n - 1; i >= 0; i--) {
        if (head >= queue[i])
            break;
        seek += abs(head - queue[i]);
        head = queue[i];
    }
    printf("CSCAN algorithm: Total seek time = %d\n", seek);
}

void SJF(int queue[], int head, int n)
{
    int seek = 0, min, pos;
    int cur_track = head;

    for (int i = 0; i < n; i++) {
        min = INT_MAX;
        for (int j = 0; j < n; j++) {
            if (queue[j] != INT_MAX && abs(queue[j] - cur_track) < min) {
                pos = j;
                min = abs(queue[j] - cur_track);
            }
        }
        seek += min;
        cur_track = queue[pos];
        queue[pos] = INT_MAX;
    }
    printf("SJF algorithm: Total seek time = %d\n", seek);
}

int main()
{
    int queue[] = { 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130 };
    int head = 143;
    int n = sizeof(queue) / sizeof(queue[0]);

    FCFS(queue, head, n);
    SSTF(queue, head, n);
    SCAN(queue, head, n);
    CSCAN(queue, head, n);
    SJF(queue, head, n);

    return 0;
}

以上代码中包含了五种不同的磁盘调度算法的实现，可以通过修改队列和磁头的初始位置来进行测试。不同算法之间的差异主要在于对磁道的访问顺序不同，因此在实际应用中需要根据实际情况选择最优的算法。