-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathSortAlgs.java
More file actions
202 lines (172 loc) · 4.39 KB
/
SortAlgs.java
File metadata and controls
202 lines (172 loc) · 4.39 KB
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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
package com.algs;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Collections;
public class SortAlgs {
// 算法可视化网站：https://visualgo.net/sorting
public static void main(String[] str) throws ClassNotFoundException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, InstantiationException{
// Integer, Double String, File and URL have implements Comparable interface
Integer[] a = new Integer[10];
for(Integer i = 0; i < 10; i++){
a[i] = i;
}
Class classType = Class.forName("com.algs.SortAlgs");
Method[] methods = classType.getDeclaredMethods();
for (Method methed : methods) {
/* Collections.shuffle(Arrays.asList(a));
methed.invoke(classType.newInstance(), a);*/
System.out.println(methed);
System.out.println(methed.getName());
}
Collections.shuffle(Arrays.asList(a));
bubble(a);
System.out.println(isSorted(a));
System.out.println(Arrays.toString(a));
Collections.shuffle(Arrays.asList(a));
select(a);
System.out.println(isSorted(a));
System.out.println(Arrays.toString(a));
Collections.shuffle(Arrays.asList(a));
insertion(a);
System.out.println(isSorted(a));
System.out.println(Arrays.toString(a));
Collections.shuffle(Arrays.asList(a));
shell(a);
System.out.println(isSorted(a));
System.out.println(Arrays.toString(a));
Collections.shuffle(Arrays.asList(a));
sortMerge(a);
System.out.println(isSorted(a));
System.out.println(Arrays.toString(a));
}
public static void exch(Comparable[] arr, int i, int j) {
Comparable t = arr[i];
arr[i] = arr[j];
arr[j] = t;
}
public static boolean less(Comparable v, Comparable w) {
return v.compareTo(w) < 0;
}
public static boolean isSorted(Comparable[] arr) {
for (int i = 1; i < arr.length; i++) {
if (less(arr[i], arr[i - 1])) {
return false;
}
}
return true;
}
// bubble sort
/**
* 每次将最大的值下沉到最下面 时间复杂度：O(n^2)，空间复杂度：O(n)
*
* @param arr
*/
public static void bubble(Comparable[] arr) {
for (int i = 0; i < arr.length; i++) {
for (int j = 1; j < arr.length - i; j++) {
if (less(arr[j], arr[j - 1])) {
exch(arr, j, j - 1);
}
}
}
}
// selection sort
/**
* 每次选择最小的一个数排在最前面 时间复杂度：O(n^2)，空间复杂度：O(n)
*
* @param arr
*/
public static void select(Comparable[] arr) {
for (int i = 0; i < arr.length; i++) {
int min = i;
for (int j = i + 1; j < arr.length; j++) {
if (less(arr[j], arr[min])) {
min = j;
}
}
exch(arr, i, min); // 和最小的元素交换
}
}
// insertion sort
/**
* 当前索引左边的所有元素都是有序的，但最终位置不确定，将当前元素与索引左边的元素比较，直到移动到合适的位置
* 时间复杂度：O(n^2)，空间复杂度：O(n)
*
* @param arr
*/
public static void insertion(Comparable[] arr) {
for (int i = 1; i < arr.length; i++) {
// 将arr[i], 插入到前面已经排序好的数组中
for (int j = i; j > 0; j--) {
if (less(arr[j], arr[j - 1])) {
exch(arr, j, j - 1);
}
}
}
}
// shell sort
/**
* 基于插入排序的快速排序算法
*
* @param arr
*/
public static void shell(Comparable[] arr) {
int N = arr.length;
int h = 1;
while (h < N / 3) {
h = 3 * h + 1;
}
while (h >= 1) {
for (int i = h; i < N; i++) {
for (int j = i; j >= h; j--) {
if (less(arr[j], arr[j - h])) {
exch(arr, j, j - h);
}
}
}
h = h / 3;
}
}
private static Comparable[] aux;
// merge sort, 归并排序
/**
*
* @param arr
*/
private static void sortMerge(Comparable[] arr) {
aux = new Comparable[arr.length];
sortMerge(arr, 0, arr.length - 1);
}
private static void sortMerge(Comparable[] arr, int lo, int hi){
if(hi <= lo){
return;
}
int mid = lo + (hi - lo)/2;
sortMerge(arr, lo, mid);
sortMerge(arr, mid + 1, hi);
merge(arr, lo, mid, hi);
}
public static void merge(Comparable[] arr, int lo, int mid, int hi){
int i = lo, j = mid + 1;
for(int k = lo; k <= hi; k++){
aux[k] = arr[k];
}
for(int k = lo; k <= hi; k++){
if (i > mid) arr[k] = aux[j++];
else if (j > hi) arr[k] = aux[i++];
else if (less(aux[j], aux[i])) arr[k] = aux[j++];
else arr[k] = aux[i++];
}
}
// quick sort
/**
*
* @param arr
*/
public static void quick(Comparable[] arr) {
}
// heap sort
public static void heap(Comparable[] arr) {
}
}