FIFO算法，优先数调度算法，时间片轮转调度算法进程调度代码

FIFO算法的进程调度代码：

#include <stdio.h>

int main()
{
    int n, bt[20], wt[20], tat[20], avwt = 0, avtat = 0, i, j;
    printf("Enter total number of processes (maximum 20): ");
    scanf("%d", &n);

    printf("\nEnter Process Burst Time\n");
    for(i = 0; i < n; i++)
    {
        printf("P[%d]: ", i+1);
        scanf("%d", &bt[i]);
    }

    wt[0] = 0;
    for(i = 1; i < n; i++)
    {
        wt[i] = 0;
        for(j = 0; j < i; j++)
            wt[i] += bt[j];
    }

    printf("\nProcess\tBurst Time\tWaiting Time\tTurnaround Time");

    for(i = 0; i < n; i++)
    {
        tat[i] = bt[i] + wt[i];
        avwt += wt[i];
        avtat += tat[i];
        printf("\nP[%d]\t%d\t\t%d\t\t%d", i+1, bt[i], wt[i], tat[i]);
    }

    avwt /= i;
    avtat /= i;
    printf("\n\nAverage Waiting Time: %d", avwt);
    printf("\nAverage Turnaround Time: %d", avtat);
    return 0;
}

优先数调度算法的进程调度代码：

#include <stdio.h>

int main()
{
    int n, bt[20], wt[20], tat[20], p[20], pr[20], i, j, temp;
    float avwt = 0, avtat = 0;

    printf("Enter total number of processes (maximum 20): ");
    scanf("%d", &n);

    printf("\nEnter Burst Time and Priority\n");
    for(i = 0; i < n; i++)
    {
        printf("P[%d]: ", i+1);
        scanf("%d %d", &bt[i], &pr[i]);
        p[i] = i+1;
    }

    for(i = 0; i < n; i++)
    {
        for(j = i+1; j < n; j++)
        {
            if(pr[i] > pr[j])
            {
                temp = pr[i];
                pr[i] = pr[j];
                pr[j] = temp;

                temp = bt[i];
                bt[i] = bt[j];
                bt[j] = temp;

                temp = p[i];
                p[i] = p[j];
                p[j] = temp;
            }
        }
    }

    wt[0] = 0;

    for(i = 1; i < n; i++)
    {
        wt[i] = 0;
        for(j = 0; j < i; j++)
            wt[i] += bt[j];

        avwt += wt[i];
    }

    avwt /= i;

    printf("\nProcess\tBurst Time\tWaiting Time\tTurnaround Time");

    for(i = 0; i < n; i++)
    {
        tat[i] = bt[i] + wt[i];
        avtat += tat[i];
        printf("\nP[%d]\t%d\t\t%d\t\t%d", p[i], bt[i], wt[i], tat[i]);
    }

    avtat /= i;
    printf("\n\nAverage Waiting Time: %f", avwt);
    printf("\nAverage Turnaround Time: %f", avtat);

    return 0;
}

时间片轮转调度算法的进程调度代码：

#include <stdio.h>

int main()
{
    int n, bt[20], wt[20], tat[20], rt[20], i, j, time, remain, flag=0, tq;
    float avwt = 0, avtat = 0;

    printf("Enter total number of processes (maximum 20): ");
    scanf("%d", &n);

    remain = n;

    printf("\nEnter Burst Time\n");
    for(i = 0; i < n; i++)
    {
        printf("P[%d]: ", i+1);
        scanf("%d", &bt[i]);
        rt[i] = bt[i];
    }

    printf("Enter Time Quantum: ");
    scanf("%d", &tq);

    printf("\nProcess\tBurst Time\tWaiting Time\tTurnaround Time\n");

    for(time = 0, i = 0; remain != 0;)
    {
        if(rt[i] <= tq && rt[i] > 0)
        {
            time += rt[i];
            rt[i] = 0;
            flag = 1;
        }
        else if(rt[i] > 0)
        {
            rt[i] -= tq;
            time += tq;
        }

        if(rt[i] == 0 && flag == 1)
        {
            remain--;
            wt[i] = time - bt[i];
            tat[i] = time;
            avwt += wt[i];
            avtat += tat[i];
            printf("P[%d]\t%d\t\t%d\t\t%d\n", i+1, bt[i], wt[i], tat[i]);
            flag = 0;
        }

        if(i == n-1)
            i = 0;
        else if(time >= i+1)
            i++;
    }

    avwt /= n;
    avtat /= n;
    printf("\nAverage Waiting Time: %f", avwt);
    printf("\nAverage Turnaround Time: %f", avtat);

    return 0;
}