本文實例為大家分享了java實現頁面置換算法的具體代碼，供大家參考，具體內容如下
原理就不說了，直接上代碼
FIFO
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
import java.util.ArrayList;import java.util.List;import utils.ListUtils;/** * * * @author cnkeysky * */public class FIFO { public void run() { String[] inputStr = {"1", "2", "3", "4", "2", "1", "2", "3", "5", "2", "3", "7", "6"}; // 內存塊 int memory = 3; List<String> list = new ArrayList<>(); for(int i = 0; i < inputStr.length; i++){ if(i == 0){ list.add(inputStr[i]); System.out.println("第"+ i +"次訪問：\t\t" + ListUtils.listToString(list)); }else { if(ListUtils.find(list, inputStr[i])){ System.out.println("第" + i + "次" + "訪問：\t\t" + ListUtils.listToString(list)); }else{ if(list.size() < memory){ list.add(inputStr[i]); }else{ list.remove(0); list.add(inputStr[i]); } System.out.println("第" + i + "次" + "訪問：\t\t" + ListUtils.listToString(list)); } } } }} |
LRU
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
import utils.ListUtils;import java.util.ArrayList;import java.util.List;/** * 最近最久未用置換算法 * @author cnkeysky * */public class LRU { public static void main(String[] args) { String[] inputStr = {"6", "7", "6", "5", "9", "6", "8", "9", "7", "6", "9", "6"}; // 內存塊 int memory = 3; List<String> list = new ArrayList<>(); for(int i = 0; i < inputStr.length; i++){ if(i == 0){ list.add(inputStr[i]); System.out.println("第"+ i +"次訪問：\t\t" + ListUtils.listToString(list)); }else { if(ListUtils.find(list, inputStr[i])){ // 存在字符串，則獲取該下標 int index = ListUtils.findIndex(list, inputStr[i]); // 下標不位于棧頂時，且list大小不為1時 if(!(list.get(list.size() - 1)).equals(inputStr[i]) && list.size() != 1) { String str = list.get(index); list.remove(index); list.add(str); } System.out.println("第" + i + "次" + "訪問：\t\t" + ListUtils.listToString(list)); }else{ if(list.size()>= memory) { list.remove(0); list.add(inputStr[i]); System.out.println("第" + i + "次" + "訪問：\t\t" + ListUtils.listToString(list)); }else { list.add(inputStr[i]); System.out.println("第" + i + "次" + "訪問：\t\t" + ListUtils.listToString(list)); } } } } }} |
Clock
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
import java.util.ArrayList;import java.util.List;import utils.ListUtils;/** * * * @author cnkeysky * */public class Clock { public static void main(String[] args) { String[] inputStr = {"6", "7", "6", "5", "9", "6", "8", "9", "7", "6", "9", "6"}; List<String> list = new ArrayList<>(); // 內存塊 int memory = 3; // 缺頁次數 int count = 0; String[] clock = new String[memory]; int indexNext = 0; int index = 0; // 初始化時鐘 for(int i = 0; i < memory; i++) { clock[i] = "0"; } for(int i = 0; i < inputStr.length; i++) { int indexPre = 0; if (i == 0) { list.add(inputStr[i]); clock[indexNext] = "1"; indexNext++; System.out.println("第"+ i +"次訪問：\t\t" + ListUtils.listToString(list)); }else { if(ListUtils.find(list, inputStr[i])) { indexPre = ListUtils.findIndex(list, inputStr[i]); if(clock[indexPre].equals("0")) { clock[indexPre] = "1"; } count++; System.out.println("第"+ i +"次訪問：\t\t" + ListUtils.listToString(list)); }else { if(list.size() < memory) { list.add(inputStr[i]); clock[indexNext] = "1"; indexNext++; System.out.println("第"+ i +"次訪問：\t\t" + ListUtils.listToString(list)); }else { index = ListUtils.findZero(indexNext, clock, memory); list.remove(index); list.add(index, inputStr[i]); clock[index] = "1"; indexNext = index + 1; System.out.println("第"+ i +"次訪問：\t\t" + ListUtils.listToString(list)); } } } if(indexNext > memory - 1) { indexNext = Math.abs(memory - indexNext); } } System.out.println("缺頁次數：" + (inputStr.length-count)); }} |
工具類ListUtils
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
import java.util.List;public class ListUtils { public ListUtils() { } /** * 輸出 * @param list 將List轉為數組并輸出, out: 2, 3, 4 * @return */ public static String listToString(List list){ StringBuffer content = new StringBuffer(); for(int i = 0; i < list.size(); i++){ content.append(list.get(i)); if(i < list.size() - 1){ content.append(","); } } return content.toString(); } /** * 在list中查找是否有str * @param list * @param str * @return */ public static boolean find(List<String> list, String str){ boolean flag = false; for(String lis : list){ if(lis.equals(str)){ flag = true; } } return flag; } /** * 在List中查找是否有String,如果有返回下標, 否則返回 -1 * @param list * @param str * @return */ public static int findIndex(List<String> list, String str) { int index = 0; for(String lis : list) { if(lis.equals(str)) { return index; } index++; } return -1; } public static boolean clockJudge(String[] clock, int index) { if(clock[index].equals("0")) { return true; } return false; } /** * * @param index 下標 * @param clock 時鐘 * @param range 當前使用內存塊 * @return */ public static int findZero(int index, String[] clock, int range) { while(true) { if(clock[index].equals("0")) { break; }else { clock[index] = "0"; index++; if(index > range-1) { index = Math.abs(range - index); } } } return index; } /** * 在數組中查找是否存在該字符串 * @param obj * @param str * @return */ public static boolean strJudge(Object[] obj, String str) { boolean flag = false; if(obj == null) { return flag; } for(int i = 0; i < obj.length; i++) { if(str.equals(obj[i])) { flag = true; break; } } return flag; } /** * 獲取二維數組中同一列的行的長度 * @param str 數據 * @param length 二維數組的列 * @param memory 內存塊 * @return * */ public static int findNull(Object[][] str, int length, int memory) { int index = 0; if(str == null) { return -1; } for(int i = 0; i < memory; i++) { if(str[i][length] != null) { index = i; } } return index; }} |
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
原文鏈接：https://blog.csdn.net/cnkeysky/article/details/80639376
