CPU模拟，随机化突发、等待和优先级

Question

我在这里编写了一个用于CPU模拟的用户交互代码，在这里用户将输入突发时间的数量、等待时间和优先级。我想删除该功能并将其替换为随机化，它将随机化突发时间、等待时间和优先级的数量。不能有 0（零），也不能有相同的值。我真的需要这个帮助，因为我真的不知道如何随机化。

import java.applet.*;
import java.awt.*;
import java.io.*;
import java.util.*;
import java.lang.*;

/*
<applet code="finalcase" height=500 width=700>
</applet>
*/

public class finalcase extends Applet{
    int apw1[];
    int p[];
    int i=0,n,n1;
    Graphics g= getGraphics();

public void init(){
    try{
        BufferedReader obj=new BufferedReader(new InputStreamReader (System.in));
        System.out.println("ENTER no. of processes:");
        n=Integer.parseInt(obj.readLine());

        int ch;
        int bt[]=new int[n];

        do{
            System.out.println("MENU FOR CPU SCHEDULING");          
            System.out.println("1.PRIORITY method (non-preemptive)");
            System.out.println("2.PRIORITY method (preemptive)");
            System.out.println("3.EXIT");
            System.out.println("ENTER YOUR CHOICE");

            ch=Integer.parseInt(obj.readLine());

        switch(ch){
        case 1: //Non-Preemptive Priority
            {
                for( i=0;i<n;i++){
                    System.out.println("ENTER burst time for each process: p"+(i+1));
                    bt[i]=Integer.parseInt(obj.readLine());
                }

                n1=n;
                int pr[]=new int[n];
                int pr1[]=new int[n];
                float t=0;
                int temp;
                int turn[]=new int[n];
                p=new int[n];
                apw1=new int[n+1];
                apw1[0]=0;
                float tu=0;


                for(i=0;i<n;i++){
                    System.out.println("Enter the priority for p"+(i+1));
                    pr[i]=Integer.parseInt(obj.readLine());
                }

                for(i=0;i<n;i++){
                    pr1[i]=pr[i];
                }

                for( i=0;i<n;i++)
                    for(int j=i+1;j<n;j++)
                        if(pr1[i]>pr1[j]){
                            temp=pr1[i];
                            pr1[i]=pr1[j];
                            pr1[j]=temp;
                        }

                        for( i=0;i<n;i++)
                            for(int j=0;j<n;j++)
                                if(pr1[i]==pr[j])
                                    p[i]=j+1;
                            for(i=0;i<n;i++){
                                int k=p[i];
                                apw1[i+1]=bt[k-1]+apw1[i];
                            }

                            for( i=0;i<n;i++){
                                System.out.println("individual waiting time for process p"+p[i]+"is"+apw1[i]+" ");
                            }

                            for( i=0;i<n;i++)
                                t+=apw1[i];
                                float avg=t/n;
                                System.out.println("average waiting time is:"+avg);

                            for( i=0;i<n;i++){
                                int k=p[i];
                                turn[i]=bt[k-1]+apw1[i];
                                System.out.println("turnaround time for process p"+p[i]+"is"+turn[i]+" ");
                            }

                            for( i=0;i<n;i++)
                                tu+=turn[i];

                                float avg1=tu/n;
                                System.out.println("average turn-around time is:"+avg1);
                    paint(g);
                }//end of 1st case
            break;

        case 2:
            {
                    int total=0,k=0,co=0,small=999,sp=0,sp1=0,x=0,count=0;
                    int pro[][]=new int[n][4];
                    int wt[]=new int[n];
                    int wt1[]=new int[n];
                    int bt1[]=new int[n];
                    int tt[]=new int[n];
                    apw1=new int [20];
                    p=new int[20];

                for(int i=0;i<n;i++){
                    pro[i][0]=i;
                    System.out.print("Burst Time for P"+i+" :");
                    pro[i][3]=Integer.parseInt(obj.readLine());
                    total+=pro[i][3];
                    System.out.print("Arrival Time for P"+i+" :");
                    pro[i][2]=Integer.parseInt(obj.readLine());
                    System.out.print("Priority for P"+i+" :");
                    pro[i][1]=Integer.parseInt(obj.readLine());
                }

                for(int i=0;i<n;i++)
                    wt1[i]=pro[i][2];

                for(int i=0;i<n;i++)
                    bt1[i]=pro[i][3];

                for(int i=0;i<n;i++)
                    for(int j=i+1;j<n;j++)
                        if(pro[i][2]>pro[j][2]) {
                            int temp[]=pro[i];
                            pro[i]=pro[j];
                            pro[j]=temp;
                        }

                for(int i=1;i<=total;i++){
                    small=999;
                        for(int j=co;j<n;j++)
                            if(k>=pro[j][2])
                            co++;
                        for(int j=0;j<co;j++){
                            if(small>pro[j][1]&&pro[j][3]!=0){
                                small=pro[j][1];
                                sp=pro[j][0];
                                sp1=j;
                            }
                        }

                        if(p[x]==sp){
                            apw1[x+1]++;
                        }else{
                            x++;
                            p[x]=sp;
                            apw1[x+1]=apw1[x];
                            apw1[x+1]++;
                            count++;
                        }

                    pro[sp1][3]-=1;

                        if(pro[sp1][3]==0)
                            tt[sp1]=i;

                            for(int j=0;j<n;j++){
                                if(pro[j][3]!=0&&j!=sp)
                                    wt[j]+=1;
                            }
                                k++;
                  }//end of main for loop

                for(int i=0;i<n;i++)
                    for(int j=i+1;j<n;j++)
                        if(pro[i][0]>pro[j][0]){
                            int temp[]=pro[i];
                            pro[i]=pro[j];
                            pro[j]=temp;
                            int tem=wt[i],tem1=tt[i];
                            wt[i]=wt[j];
                            wt[j]=tem;
                            tt[i]=tt[j];
                            tt[j]=tem1;
                        }

                System.out.println();

                for(int m=0;m<=count;m++)
                    p[m]+=1;

                double awt=0.0,att=0.0;

                System.out.println();
                for (int i = 0; i<n; i++){
                    System.out.println("waiting time for process p "+i+"  "+(wt[i]-wt1[i]));
                    awt+=(wt[i]-wt1[i]);
                    att+=(wt[i]-wt1[i]+bt1[i]);
                }

                for (int i = 0; i<n; i++){
                    System.out.println("turnaround time for process p"+i+"  "+(wt[i]-wt1[i]+bt1[i]));
                }

                System.out.println("Average waiting time : "+(awt/n));
                System.out.println("Average turnaround time : "+(att/n));
                n1=count+1;
                paint(g);


            }//end of case 2
        }//end of switch

       }while(ch!=3); //end of do-while loop
      }catch (Exception e){
         }//end of try-catch
   }//end of init method


   public void paint(Graphics g){
        for(int j=1;j<=n1;j++){
            g.drawRect(50,50,(apw1[j]*20),30);
            g.drawString("p"+p[j-1],(55+(apw1[j-1]*20)),70);    
            g.drawString(""+apw1[j-1],50+(apw1[j-1]*20),100);

            try {
                Thread.sleep(500);
            }catch (Exception e) {
                ;
            }//end of try-catch
        }//end of for   
        g.drawString(""+apw1[n1],50+(apw1[n1]*20),100);
    }//end of painter
}//end of class

Answer 1

使用java.util.Random类生成随机数。

Random r = new Random();
int randomInt = r.nextInt(5) + 1; // int between 1-5
double randomDouble = r.nextDouble(); // between 0.0 and 0.9999999...

如果生成该数字并获得重复值，请再次生成它。您可以使用任何您喜欢的算法来拒绝数字。