短作业优先算法完整代码C语言

短作业优先（Shortest Job First, SJF）算法是一种在单个处理器调度中常用的作业调度策略。它优先处理最短的作业，这样可以更快地响应和减少平均周转时间。以下是一个简单的C语言实现，使用链表表示作业队列：

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

// 作业结构体
typedef struct Job {
    int id;
    int burst_time; // 作业运行所需的时间
    struct Job* next;
} Job;

// 初始化链表
Job* initQueue() {
    Job* queue = (Job*)malloc(sizeof(Job));
    queue->id = 0;
    queue->burst_time = 0;
    queue->next = NULL;
    return queue;
}

// 添加作业到链表
void addJob(Job* queue, int id, int burst_time) {
    Job* newNode = (Job*)malloc(sizeof(Job));
    newNode->id = id;
    newNode->burst_time = burst_time;
    newNode->next = queue->next;
    queue->next = newNode;
}

// 比较作业的大小并进行调度
int compareJobs(Job* job1, Job* job2) {
    return job1->burst_time < job2->burst_time;
}

// 执行SJF调度
void sjfScheduler(Job* queue) {
    if (queue == NULL) return;

    Job* currentJob = queue;
    Job* minJob = queue;
    while (currentJob != NULL) {
        if (compareJobs(currentJob, minJob)) {
            minJob = currentJob;
        }
        currentJob = currentJob->next;
    }

    printf("Current job: %d, Burst time: %d\n", minJob->id, minJob->burst_time);
    // 假设执行了minJob，然后更新链表
    queue->next = minJob->next;
    free(minJob);
}

// 主函数
int main() {
    srand(time(0)); // 为了示例随机生成作业

    Job* queue = initQueue();
    int numJobs, i;
    printf("Enter number of jobs: ");
    scanf("%d", &numJobs);

    for (i = 0; i < numJobs; i++) {
        int id, burstTime;
        printf("Enter job %d ID and burst time: ", i + 1);
        scanf("%d %d", &id, &burstTime);
        addJob(queue, id, burstTime);
    }

    sjfScheduler(queue);
    return 0;
}