-
Notifications
You must be signed in to change notification settings - Fork 0
/
QuickSort.java
82 lines (77 loc) · 1.86 KB
/
QuickSort.java
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
package sort;
/**
* @author ahscuml
* @date 2018/7/11
* @time 16:28
*/
public class QuickSort {
private QuickSort() {
}
public static void sort(Comparable[] arr) {
int n = arr.length;
sort(arr, 0, n - 1);
}
/**
* 把partion拟合到排序算法里的写法
* */
public static void sort(Comparable[] arr, int l, int r) {
if (l >= r) {
return;
}
Comparable e = arr[l];
int j = l;
for (int i = l + 1; i <= r; i++) {
if (arr[i].compareTo(e) < 0) {
j++;
swap(arr, j, i);
}
}
swap(arr, l, j);
j--;
sort(arr, l, j);
sort(arr, j + 2, r);
}
/**
* 快速排序算法
*/
/*private static void sort(Comparable[] arr, int l, int r) {
if( l >= r ) {
return;
}
int p = partition(arr, l, r);
sort(arr, l, p-1);
sort(arr, p+1, r);
}
*//**
* 对arr[l...r]部分进行partition操作
* 返回p, 使得arr[l...p-1] < arr[p] ; arr[p+1...r] > arr[p]
*//*
private static int partition(Comparable[] arr, int l, int r) {
Comparable v = arr[l];
int j = l;
for (int i = l + 1; i <= r; i++) {
if (v.compareTo(arr[i]) > 0) {
j++;
swap(arr, i, j);
}
}
swap(arr, l, j);
return j;
}*/
/**
* 交换函数
*/
private static void swap(Comparable[] arr, int i, int j) {
Comparable temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
/**
* 测试用例
*/
public static void main(String[] args) {
int N = 1000000;
Integer[] arr = SortTestHelper.generateRandomArray(N, 0, 100000);
SortTestHelper.testSort("sort.QuickSort", arr);
}
}