psa优先调度算法的c语言,FCFS、SJF、PSA、RR、MFS作业调度C语言实现

以下是常见的作业调度算法的C语言实现：

1. FCFS（先来先服务）

#include <stdio.h>

int main()
{
    int n, i;
    float avg_tat = 0, avg_wt = 0;
    int burst[20], tat[20], wt[20];

    printf("Enter the number of processes: ");
    scanf("%d", &n);

    printf("Enter the burst time for each process:\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]: ", i+1);
        scanf("%d", &burst[i]);
    }

    tat[0] = burst[0];
    wt[0] = 0;
    for(i=1; i<n; i++)
    {
        tat[i] = tat[i-1] + burst[i];
        wt[i] = tat[i-1];
    }

    printf("\nProcess\tBurst Time\tTurnaround Time\tWaiting Time\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]\t%d\t\t%d\t\t%d\n", i+1, burst[i], tat[i], wt[i]);
        avg_tat += tat[i];
        avg_wt += wt[i];
    }

    avg_tat /= n;
    avg_wt /= n;
    printf("\nAverage Turnaround Time: %.2f", avg_tat);
    printf("\nAverage Waiting Time: %.2f", avg_wt);

    return 0;
}

2. SJF（短作业优先）

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

struct process
{
    int id;
    int burst;
    int arrival;
    int tat;
    int wt;
};

void swap(struct process *a, struct process *b)
{
    struct process temp = *a;
    *a = *b;
    *b = temp;
}

void sort(struct process arr[], int n)
{
    int i, j;
    for(i=0; i<n-1; i++)
    {
        for(j=0; j<n-i-1; j++)
        {
            if(arr[j].burst > arr[j+1].burst)
            {
                swap(&arr[j], &arr[j+1]);
            }
        }
    }
}

int main()
{
    int n, i, j;
    float avg_tat = 0, avg_wt = 0;
    struct process p[20];

    printf("Enter the number of processes: ");
    scanf("%d", &n);

    printf("Enter the arrival time and burst time for each process:\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]: ", i+1);
        p[i].id = i+1;
        scanf("%d %d", &p[i].arrival, &p[i].burst);
    }

    sort(p, n);

    p[0].tat = p[0].burst;
    p[0].wt = 0;
    for(i=1; i<n; i++)
    {
        int sum = 0;
        for(j=0; j<i; j++)
        {
            sum += p[j].burst;
        }
        p[i].tat = sum + p[i].burst - p[i].arrival;
        p[i].wt = p[i-1].wt + p[i-1].burst - p[i].arrival;
        if(p[i].wt < 0)
        {
            p[i].wt = 0;
        }
    }

    printf("\nProcess\tArrival Time\tBurst Time\tTurnaround Time\tWaiting Time\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]\t%d\t\t%d\t\t%d\t\t%d\n", p[i].id, p[i].arrival, p[i].burst, p[i].tat, p[i].wt);
        avg_tat += p[i].tat;
        avg_wt += p[i].wt;
    }

    avg_tat /= n;
    avg_wt /= n;
    printf("\nAverage Turnaround Time: %.2f", avg_tat);
    printf("\nAverage Waiting Time: %.2f", avg_wt);

    return 0;
}

3. PSA（优先级调度算法）

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

struct process
{
    int id;
    int burst;
    int priority;
    int tat;
    int wt;
};

void swap(struct process *a, struct process *b)
{
    struct process temp = *a;
    *a = *b;
    *b = temp;
}

void sort(struct process arr[], int n)
{
    int i, j;
    for(i=0; i<n-1; i++)
    {
        for(j=0; j<n-i-1; j++)
        {
            if(arr[j].priority > arr[j+1].priority)
            {
                swap(&arr[j], &arr[j+1]);
            }
        }
    }
}

int main()
{
    int n, i, j;
    float avg_tat = 0, avg_wt = 0;
    struct process p[20];

    printf("Enter the number of processes: ");
    scanf("%d", &n);

    printf("Enter the burst time and priority for each process:\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]: ", i+1);
        p[i].id = i+1;
        scanf("%d %d", &p[i].burst, &p[i].priority);
    }

    sort(p, n);

    p[0].wt = 0;
    p[0].tat = p[0].burst;
    for(i=1; i<n; i++)
    {
        p[i].wt = p[i-1].wt + p[i-1].burst;
        p[i].tat = p[i].wt + p[i].burst;
    }

    printf("\nProcess\tBurst Time\tPriority\tTurnaround Time\tWaiting Time\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]\t%d\t\t%d\t\t%d\t\t%d\n", p[i].id, p[i].burst, p[i].priority, p[i].tat, p[i].wt);
        avg_tat += p[i].tat;
        avg_wt += p[i].wt;
    }

    avg_tat /= n;
    avg_wt /= n;
    printf("\nAverage Turnaround Time: %.2f", avg_tat);
    printf("\nAverage Waiting Time: %.2f", avg_wt);

    return 0;
}

4. RR（时间片轮转调度算法）

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

struct process
{
    int id;
    int burst;
    int remaining;
    int tat;
    int wt;
};

int main()
{
    int n, i, t = 0, count = 0, tq;
    float avg_tat = 0, avg_wt = 0;
    struct process p[20];

    printf("Enter the number of processes: ");
    scanf("%d", &n);

    printf("Enter the time quantum: ");
    scanf("%d", &tq);

    printf("Enter the burst time for each process:\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]: ", i+1);
        p[i].id = i+1;
        scanf("%d", &p[i].burst);
        p[i].remaining = p[i].burst;
    }

    while(count < n)
    {
        for(i=0; i<n; i++)
        {
            if(p[i].remaining > 0)
            {
                if(p[i].remaining > tq)
                {
                    t += tq;
                    p[i].remaining -= tq;
                }
                else
                {
                    t += p[i].remaining;
                    p[i].wt = t - p[i].burst;
                    p[i].remaining = 0;
                    count++;
                    p[i].tat = t;
                    avg_tat += p[i].tat;
                    avg_wt += p[i].wt;
                }
            }
        }
    }

    avg_tat /= n;
    avg_wt /= n;
    printf("\nProcess\tBurst Time\tTurnaround Time\tWaiting Time\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]\t%d\t\t%d\t\t%d\n", p[i].id, p[i].burst, p[i].tat, p[i].wt);
    }

    printf("\nAverage Turnaround Time: %.2f", avg_tat);
    printf("\nAverage Waiting Time: %.2f", avg_wt);

    return 0;
}

5. MFS（多级反馈队列调度算法）

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

struct process
{
    int id;
    int burst;
    int remaining;
    int priority;
    int tat;
    int wt;
};

void swap(struct process *a, struct process *b)
{
    struct process temp = *a;
    *a = *b;
    *b = temp;
}

void sort(struct process arr[], int n)
{
    int i, j;
    for(i=0; i<n-1; i++)
    {
        for(j=0; j<n-i-1; j++)
        {
            if(arr[j].priority < arr[j+1].priority)
            {
                swap(&arr[j], &arr[j+1]);
            }
        }
    }
}

int main()
{
    int n, i, j, t = 0, count = 0;
    float avg_tat = 0, avg_wt = 0;
    struct process p[20];

    printf("Enter the number of processes: ");
    scanf("%d", &n);

    printf("Enter the burst time and priority for each process:\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]: ", i+1);
        p[i].id = i+1;
        scanf("%d %d", &p[i].burst, &p[i].priority);
        p[i].remaining = p[i].burst;
    }

    sort(p, n);

    while(count < n)
    {
        for(i=0; i<n; i++)
        {
            if(p[i].remaining > 0)
            {
                if(p[i].remaining > 2)
                {
                    t += 2;
                    p[i].remaining -= 2;
                    p[i].priority--;
                }
                else
                {
                    t += p[i].remaining;
                    p[i].wt = t - p[i].burst;
                    p[i].remaining = 0;
                    count++;
                    p[i].tat = t;
                    avg_tat += p[i].tat;
                    avg_wt += p[i].wt;
                }
            }
        }
        sort(p, n);
    }

    avg_tat /= n;
    avg_wt /= n;
    printf("\nProcess\tBurst Time\tPriority\tTurnaround Time\tWaiting Time\n");
    for(i=0; i<n; i++)
    {
        printf("P[%d]\t%d\t\t%d\t\t%d\t\t%d\n", p[i].id, p[i].burst, p[i].priority, p[i].tat, p[i].wt);
    }

    printf("\nAverage Turnaround Time: %.2f", avg_tat);
    printf("\nAverage Waiting Time: %.2f", avg_wt);

    return 0;
}