1 import java.util.Arrays;
2 import java.util.Random;
3
4 /**
5 * Created by Administrator on 2019/11/25.
6 */
7 public class Application {
8 public static void main(String[] args) {
9 int[] array=new int[8];
10 Sort sort=new Sort();
11 fillArray(array);
12 System.out.println("快速排序前："+ Arrays.toString(array));
13 sort.quickSort(array,0,array.length-1);
14 System.out.println("排序后："+ Arrays.toString(array));
15 System.out.println("---------------------------------------");
16
17 fillArray(array);
18 System.out.println("冒泡排序前："+ Arrays.toString(array));
19 sort.bubbleSort(array);
20 System.out.println("排序后："+ Arrays.toString(array));
21 System.out.println("---------------------------------------");
22
23 fillArray(array);
24 System.out.println("插入排序前："+ Arrays.toString(array));
25 sort.insertSort(array);
26 System.out.println("排序后："+ Arrays.toString(array));
27 System.out.println("---------------------------------------");
28
29
30 }
31 public static void fillArray(int[] array){
32 Random random=new Random();
33 for(int i=0;i<array.length;i++){
34 array[i]=random.nextInt(50);
35 }
36 }
37 public static class Sort{
38 //冒泡排序
39 private void bubbleSort(int[] nums){
40 int temp;
41 for(int i=1;i<nums.length;i++){
42 for(int j=0;j<nums.length-i;j++){
43 if(nums[j]>nums[j+1]){
44 temp=nums[j];
45 nums[j]=nums[j+1];
46 nums[j+1]=temp;
47 }
48 }
49 }
50 }
51 //选择排序
52 private void selectSort(int[] nums) {
53 int index;
54 int temp;
55 for (int i = 0; i < nums.length - 1; i++) {
56 index = i;
57 for (int j = i + 1; j < nums.length; j++) {
58 if (nums[j] < nums[index]) {
59 index = j;
60 }
61 }
62 if (index != i) {
63 temp = nums[i];
64 nums[i] = nums[index];
65 nums[index] = temp;
66 }
67 }
68 }
69 //插入排序
70 private void insertSort(int[] nums){
71 int i,j,k;
72 for(i=1;i<nums.length;i++){
73 k=nums[i];
74 j=i-1;
75 while(j>=0&&nums[j]>k){
76 nums[j+1]=nums[j];
77 j--;
78 }
79 nums[j+1]=k;
80 }
81 }
82 //快速排序
83 private void quickSort(int[] array,int low,int high){
84
85 int i,j,pivot;
86 pivot=array[low];
87 i=low;
88 j=high;
89 while (i<j){
90 while(i<j&&array[j]>=pivot){
91 j--;
92 }
93 array[i]=array[j];
94 while(i<j&&array[i]<=pivot){
95 i++;
96 }
97 array[j]=array[i];
98 }
99 array[i]=pivot;
100 if(low<i){
101 quickSort(array,low,i-1);
102 }
103 if(high>i){
104 quickSort(array,i+1,high);
105 }
106
107
108 }
109 }
110
111 }
今天手写复习一下常用的几种排序