一、概述
因為這次os作業對用戶在控制臺的輸入輸出有要求，所以我花了挺多的代碼來完善控制臺的顯示。
也因為我這次要實現多個類似算法，所以將一些共性單獨提取出來作為一個類。
如果只想要和算法有關的核心代碼，看RR類的calc()即可。
實現思路：每運行一個進程，則將所有進程的remainServiceTime減去一個時間片的長度。
二、運行結果
1. 測試數據：
2. 運行結果：
三、流程圖
四、實現代碼
1. RR類(主類)
只有calc()中涉及了算法，init()和printResult()只有簡單的輸入輸出操作。
1 packagexqy.algorithm;2
3 import java.util.*;4
5 importxqy.Util.Tools;6 importxqy.been.Process;7
8 /**
9 *@authorxqy10 * @date 2018年12月19日19:14:4911 */
12 public classRR {13 private intprocessNumber;14 private ArrayListprocessList;15 private inttimeSlice;16
17 publicRR() {18 init();19 calc();20 Tools.printResult(processList);21 }22
23 private voidinit() {24 Scanner sc = newScanner(System.in);25
26 System.out.print(" Please enter the slice time:");27 timeSlice =sc.nextInt();28 System.out.print(" please enter the process num:");29 processNumber =sc.nextInt();30
31 processList = new ArrayList();32 for (int i = 0; i < processNumber; i++) {33 processList.add(newProcess());34 }35
36 System.out.println(" Please enter each process arrival time:");37 for (int i = 0; i < processNumber; i++) {38 System.out.print(" Process" + (i + 1) + ":");39 processList.get(i).setArrivalTime(sc.nextInt());40 }41
42 System.out.println(" Please enter each process service time:");43 for (int i = 0; i < processNumber; i++) {44 System.out.print(" Process" + (i + 1) + ":");45 int servicesTime =sc.nextInt();46
47 processList.get(i).setServicesTime(servicesTime);48 processList.get(i).setRemainServiceTime(servicesTime);49 }50 }51
52 private voidcalc() {53 int timeNow = 0;54 int processRemain =processNumber;55 booleannoProcessRunInThisTurn;56 Process opProcess;57
58 while (processRemain != 0) {59 noProcessRunInThisTurn = true;60
61 for (int i = 0; i < processNumber; i++) {62 opProcess =processList.get(i);63
64 if ((opProcess.getRemainServiceTime() > 0)65 && (timeNow >=opProcess.getArrivalTime())) {66 //First time
67 if (opProcess.getServicesTime() ==opProcess68 .getRemainServiceTime()) {69 int waitTime = timeNow -opProcess.getArrivalTime();70
71 opProcess.setStartTime(timeNow);72 opProcess.setWaitTime(waitTime);73 }74
75 //Calculating remain service time
76 int remainServiceTime =opProcess.getRemainServiceTime()77 -timeSlice;78 opProcess.setRemainServiceTime(remainServiceTime);79
80 //Last time
81 if (remainServiceTime <= 0) {82 int completionTime = timeNow + timeSlice; //The process ends when the current slice is completed.
83 int turnAroundTime =completionTime84 -opProcess.getArrivalTime();85 double turnAroundTimeWithWeight = 1.0 *turnAroundTime86 /opProcess.getServicesTime();87
88 opProcess.setCompletionTime(completionTime);89 opProcess.setTurnAroundTime(turnAroundTime);90 opProcess91 .setTurnAroundTimeWithWeight(turnAroundTimeWithWeight);92 processRemain--;93 }94
95 timeNow +=timeSlice;96 noProcessRunInThisTurn = false;97
98 System.out.println(" #STEP# Process" + (i + 1)99 + " remain service time:"
100 +opProcess.getRemainServiceTime()101 + " , timeBefore:" + (timeNow - 1) + ", timeNow:"
102 +timeNow103 + ((remainServiceTime <= 0) ? " Finish" : ""));104 } else{105 //do noting, because this process has been completed or hasn`t arrived.
106 }107 }108
109 //Means no process could run, because they have arrived.
110 if ((processRemain > 0) &&noProcessRunInThisTurn) {111 timeNow +=timeSlice;112 }113 }114 }115 }
2. Process類
模擬了進程，對屬性進行了封裝。
1 package xqy.been;
2
3 public class Process {
4 private int arrivalTime;
5 private int servicesTime;
6 private int remainServiceTime;
7 private int startTime;
8 private int waitTime;
9 private int completionTime;
10
11 /**
12 * turnAroundTime = completionTime - arrivalTime
13 */
14 private int turnAroundTime;
15
16 /**
17 * turnAroundTimeWithWeight = turnAroundTime / servicesTime
18 */
19 private double turnAroundTimeWithWeight;
20
21 public Process() {
22 ;
23 }
24
25 public int getArrivalTime() {
26 return arrivalTime;
27 }
28
29 public void setArrivalTime(int arrivalTime) {
30 this.arrivalTime = arrivalTime;
31 }
32
33 public int getServicesTime() {
34 return servicesTime;
35 }
36
37 public void setServicesTime(int servicesTime) {
38 this.servicesTime = servicesTime;
39 }
40
41 public int getRemainServiceTime() {
42 return remainServiceTime;
43 }
44
45 public void setRemainServiceTime(int remainServiceTime) {
46 this.remainServiceTime = remainServiceTime;
47 }
48
49 public int getStartTime() {
50 return startTime;
51 }
52
53 public void setStartTime(int startTime) {
54 this.startTime = startTime;
55 }
56
57 public int getWaitTime() {
58 return waitTime;
59 }
60
61 public void setWaitTime(int waitTime) {
62 this.waitTime = waitTime;
63 }
64
65 public int getCompletionTime() {
66 return completionTime;
67 }
68
69 public void setCompletionTime(int completionTime) {
70 this.completionTime = completionTime;
71 }
72
73 public int getTurnAroundTime() {
74 return turnAroundTime;
75 }
76
77 public void setTurnAroundTime(int turnAroundTime) {
78 this.turnAroundTime = turnAroundTime;
79 }
80
81 public double getTurnAroundTimeWithWeight() {
82 return turnAroundTimeWithWeight;
83 }
84
85 public void setTurnAroundTimeWithWeight(double turnAroundTimeWithWeight) {
86 this.turnAroundTimeWithWeight = turnAroundTimeWithWeight;
87 }
88
89 @Override
90 public String toString() {
91 return "Process [arrivalTime=" + arrivalTime + ", servicesTime="
92 + servicesTime + ", remainServiceTime=" + remainServiceTime
93 + ", startTime=" + startTime + ", waitTime=" + waitTime
94 + ", completionTime=" + completionTime + ", turnAroundTime="
95 + turnAroundTime + ", turnAroundTimeWithWeight="
96 + turnAroundTimeWithWeight + "]";
97 }
98 }
3. Tools類
因為這次要實現幾個類似的算法，所以我把每個算法中都要用到的方法都提取出來作為單獨的工具類。
也可以將這些工具方法都放入FCFS類中。
1 package xqy.Util;
2
3 import java.util.ArrayList;
4
5 import xqy.been.Process;
6
7 public class Tools {
8
9 public static double calcAverageTurnAroundTime(
10 ArrayList processList) {
11 double sum = 0;
12 for (int i = 0; i < processList.size(); i++) {
13 sum += processList.get(i).getTurnAroundTime();
14 }
15 return Math.round(sum / processList.size() * 100) / 100.0;
16 }
17
18 public static double calcAverageTurnAroundTimeWithWeight(
19 ArrayList processList) {
20 double sum = 0;
21 for (int i = 0; i < processList.size(); i++) {
22 sum += processList.get(i).getTurnAroundTimeWithWeight();
23 }
24 return Math.round(sum / processList.size() * 100) / 100.0;
25 }
26
27 public static void printResult(ArrayList processList) {
28 System.out.println("n #RESULT#");
29
30 System.out.print("tArrive:tt");
31 for (int i = 0; i < processList.size(); i++) {
32 System.out.print(processList.get(i).getArrivalTime() + "t");
33 }
34 System.out.println();
35
36 System.out.print("tService:t");
37 for (int i = 0; i < processList.size(); i++) {
38 System.out.print(processList.get(i).getServicesTime() + "t");
39 }
40 System.out.println();
41
42 System.out.print("tStart:tt");
43 for (int i = 0; i < processList.size(); i++) {
44 System.out.print(processList.get(i).getStartTime() + "t");
45 }
46 System.out.println();
47
48 System.out.print("tWait:tt");
49 for (int i = 0; i < processList.size(); i++) {
50 System.out.print(processList.get(i).getWaitTime() + "t");
51 }
52 System.out.println();
53
54 System.out.print("tFinish:tt");
55 for (int i = 0; i < processList.size(); i++) {
56 System.out.print(processList.get(i).getCompletionTime() + "t");
57 }
58 System.out.println();
59
60 System.out.print("tTurn around:t");
61 for (int i = 0; i < processList.size(); i++) {
62 System.out.print(processList.get(i).getTurnAroundTime() + "t");
63 }
64 System.out.println();
65
66 System.out.print("tTA wight:t");
67 for (int i = 0; i < processList.size(); i++) {
68 System.out.print(Math.round(processList.get(i)
69 .getTurnAroundTimeWithWeight() * 100) / 100.0 + "t");
70 }
71 System.out.println();
72
73 System.out.println("tAverage turn around time:"
74 + Tools.calcAverageTurnAroundTime(processList) + "t");
75 System.out.println("tAverage turn around time with wight:"
76 + Tools.calcAverageTurnAroundTimeWithWeight(processList));
77
78 System.out.println();
79 }
80 }
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