通过ava语言实现以下要求：选择一个调度算法，实现处理机调度。 1、设计一个按下面三种调度算法实现处理机调度的程序。 1）先来先服务 2）短进程优先或优先权高优先 3）按时间片轮转

以下是使用 Java 语言实现三种调度算法的示例代码：

1. 先来先服务（FCFS）调度算法：

import java.util.*;

public class FCFS {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter the number of processes: ");
        int n = input.nextInt();
        int[] bt = new int[n];
        int[] wt = new int[n];
        int[] tat = new int[n];
        int[] ct = new int[n];
        int sum = 0;
        float avgwt = 0, avgtat = 0;
        System.out.println("Enter the Burst Time for each process: ");
        for (int i = 0; i < n; i++) {
            System.out.print("Process " + (i + 1) + ": ");
            bt[i] = input.nextInt();
        }
        ct[0] = bt[0];
        for (int i = 1; i < n; i++) {
            ct[i] = ct[i - 1] + bt[i];
        }
        for (int i = 0; i < n; i++) {
            tat[i] = ct[i];
            wt[i] = tat[i] - bt[i];
            avgwt += wt[i];
            avgtat += tat[i];
        }
        System.out.println("\nFCFS Scheduling Algorithm:");
        System.out.println("Process\tBT\tCT\tTAT\tWT");
        for (int i = 0; i < n; i++) {
            System.out.println((i + 1) + "\t" + bt[i] + "\t" + ct[i] + "\t" + tat[i] + "\t" + wt[i]);
        }
        avgwt /= n;
        avgtat /= n;
        System.out.println("Average Waiting Time: " + avgwt);
        System.out.println("Average Turnaround Time: " + avgtat);
    }
}

2. 短进程优先或优先权高优先调度算法：

import java.util.*;

public class SJF {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter the number of processes: ");
        int n = input.nextInt();
        int[] bt = new int[n];
        int[] wt = new int[n];
        int[] tat = new int[n];
        int[] ct = new int[n];
        int sum = 0;
        float avgwt = 0, avgtat = 0;
        System.out.println("Enter the Burst Time for each process: ");
        for (int i = 0; i < n; i++) {
            System.out.print("Process " + (i + 1) + ": ");
            bt[i] = input.nextInt();
        }
        int[] p = new int[n];
        for (int i = 0; i < n; i++) {
            p[i] = i + 1;
        }
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                if (bt[i] > bt[j]) {
                    int temp = bt[i];
                    bt[i] = bt[j];
                    bt[j] = temp;
                    temp = p[i];
                    p[i] = p[j];
                    p[j] = temp;
                }
            }
        }
        ct[0] = bt[0];
        for (int i = 1; i < n; i++) {
            ct[i] = ct[i - 1] + bt[i];
        }
        for (int i = 0; i < n; i++) {
            tat[i] = ct[i];
            wt[i] = tat[i] - bt[i];
            avgwt += wt[i];
            avgtat += tat[i];
        }
        System.out.println("\nSJF Scheduling Algorithm:");
        System.out.println("Process\tBT\tCT\tTAT\tWT");
        for (int i = 0; i < n; i++) {
            System.out.println(p[i] + "\t" + bt[i] + "\t" + ct[i] + "\t" + tat[i] + "\t" + wt[i]);
        }
        avgwt /= n;
        avgtat /= n;
        System.out.println("Average Waiting Time: " + avgwt);
        System.out.println("Average Turnaround Time: " + avgtat);
    }
}

3. 按时间片轮转调度算法：

import java.util.*;

public class RoundRobin {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter the number of processes: ");
        int n = input.nextInt();
        int[] bt = new int[n];
        int[] wt = new int[n];
        int[] tat = new int[n];
        int[] ct = new int[n];
        int[] rem_bt = new int[n];
        int sum = 0, t = 0, tq;
        float avgwt = 0, avgtat = 0;
        System.out.println("Enter the Burst Time for each process: ");
        for (int i = 0; i < n; i++) {
            System.out.print("Process " + (i + 1) + ": ");
            bt[i] = input.nextInt();
            rem_bt[i] = bt[i];
        }
        System.out.print("Enter the time quantum: ");
        tq = input.nextInt();
        while (true) {
            boolean done = true;
            for (int i = 0; i < n; i++) {
                if (rem_bt[i] > 0) {
                    done = false;
                    if (rem_bt[i] > tq) {
                        t += tq;
                        rem_bt[i] -= tq;
                    } else {
                        t += rem_bt[i];
                        ct[i] = t;
                        tat[i] = ct[i];
                        wt[i] = tat[i] - bt[i];
                        avgwt += wt[i];
                        avgtat += tat[i];
                        rem_bt[i] = 0;
                    }
                }
            }
            if (done) {
                break;
            }
        }
        System.out.println("\nRound Robin Scheduling Algorithm:");
        System.out.println("Process\tBT\tCT\tTAT\tWT");
        for (int i = 0; i < n; i++) {
            System.out.println((i + 1) + "\t" + bt[i] + "\t" + ct[i] + "\t" + tat[i] + "\t" + wt[i]);
        }
        avgwt /= n;
        avgtat /= n;
        System.out.println("Average Waiting Time: " + avgwt);
        System.out.println("Average Turnaround Time: " + avgtat);
    }
}