Java中sort如何自定义排序

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?自定义排序格式

///对 num [1,n+1)区间进行自定义排序 

Arrays.sort(num,1,n+1,new Comparator<Integer>() {
    public int compare(Integer o1,Integer o2) {
        return o1-o2;///o1-o2 : 从小到大排序
    }
});    

1 Arrays.sort(num,1,n+1,new Comparator<Integer>() {    
2     public int compare(Integer o1,Integer o2) {
3         return o2-o1;///o2-o1 : 从大到小排序
4     }
5 });

PS : num 必须是 Integer类型的

?Code

 1 package Test;
 2 
 3 import java.util.Arrays;
 4 import java.util.Comparator;
 5 import java.util.Random;
 6 
 7 public class Sort {
 8 
 9     static Random random = new Random();
10     public static void main(String[] args) {
11         
12         
13         Integer[] num = new Integer[10];
14         
15         int n = random.nextInt(5)+5;
16 
17         System.out.println("测试默认排序方式");
18         R(num,n);///随机 n 个数
19         Print(num,n);
20         Arrays.sort(num,1,n+1);///[1,n+1)从小到大排序
21         Print(num,n);
22         System.out.println("+-+-+-+-+-+-+-+-+"+"\n");
23         
24         /*
25          * o1-o2 : 从小到大排序
26          * o2-o1 : 从大到小排序
27          * Math.abs(o2)-Math.abs(o1) : 绝对值从大到小排序
28          */
29         System.out.println("测试自定义排序方式");
30         R(num,n);
31         Print(num,n);
32         Arrays.sort(num,1,n+1,new Comparator<Integer>() {
33             public int compare(Integer o1,Integer o2) {
34                 return o1-o2;///o1-o2 : 从小到大排序
35             }
36         });
37         Print(num,n);
38         Arrays.sort(num,1,n+1,new Comparator<Integer>() {
39             
40             public int compare(Integer o1,Integer o2) {
41                 return o2-o1;///o2-o1 : 从大到小排序
42             }
43         });
44         Print(num,n);
45         
46         System.out.println("+-+-+-+-+-+-+-+-+"+"\n");
47     }
48     
49     public static void R(Integer[] num,int n) {
50         for(int i = 1;i <= n;i++) {
51             num[i] = random.nextInt(20);
52             if(i%2 == 0)
53                 num[i] *= -1;
54         }
55             
56     }
57     public static void Print(Integer[] num,int n) {
58         for(int i = 1;i <= n;i++)
59             System.out.print(num[i]+" ");
60         System.out.println();
61     }
62 }

View Code

?牛刀小试HDU2020

链接：绝对值排序

?Code

 1 import java.util.Arrays;
 2 import java.util.Comparator;
 3 import java.util.Random;
 4 import java.util.Scanner;
 5 
 6 public class Main{
 7 
 8     static int n;
 9     static Integer num[] = new Integer[150];
10     public static void main(String[] args) {
11         
12         Scanner cin = new Scanner(System.in);
13         
14         while(cin.hasNext()) {
15             n = cin.nextInt();
16             if(n == 0)
17                 break;
18             
19             for(int i = 1;i <= n;i++) {
20                 num[i] = cin.nextInt();
21             }
22             
23             Arrays.sort(num,1,n+1,new Comparator<Integer>(){
24                 @Override
25                 public int compare(Integer o1, Integer o2) {
26                     // TODO Auto-generated method stub
27                     return Math.abs(o2)-Math.abs(o1);
28                 }
29                 
30             });
31             for(int i = 1;i <= n;i++) {
32                 if(i != 1)
33                     System.out.print(" ");
34                 System.out.print(num[i]);
35             }
36             System.out.println();
37         }
38     }
39 
40 }

View Code

Java中sort如何自定义排序

标签：php   tin   sort   close   默认   自定义   imp   ati   targe   

原文地址：https://www.cnblogs.com/hyacinthLJP/p/14250130.html