Java程序練習-DNA sorting

描述
One measure of ``unsortedness'' in a sequence is the number of pairs of entries that are out of order with respect to each other. For instance, in the letter sequence ``DAABEC'', this measure is 5, since D is greater than four letters to its right and E is greater than one letter to its right. This measure is called the number of inversions in the sequence. The sequence ``AACEDGG'' has only one inversion (E and D)---it is nearly sorted---while the sequence ``ZWQM'' has 6 inversions (it is as unsorted as can be---exactly the reverse of sorted).

You are responsible for cataloguing a sequence of DNA strings (sequences containing only the four letters A, C, G, and T). However, you want to catalog them, not in alphabetical order, but rather in order of ``sortedness'', from ``most sorted'' to ``least sorted''. All the strings are of the same length.

輸入
The first line contains two integers: a positive integer n (0 < n <= 50) giving the length of the strings; and a positive integer m (0 < m <= 100) giving the number of strings. These are followed by m lines, each containing a string of length n.
輸出
Output the list of input strings, arranged from ``most sorted'' to ``least sorted''. Since two strings can be equally sorted, then output them according to the orginal order.
樣例輸入
10 6
AACATGAAGG
TTTTGGCCAA
TTTGGCCAAA
GATCAGATTT
CCCGGGGGGA
ATCGATGCAT
樣例輸出
CCCGGGGGGA
AACATGAAGG
GATCAGATTT
ATCGATGCAT
TTTTGGCCAA
TTTGGCCAAA

參考代碼

1. import java.io.BufferedInputStream;  
2. import java.io.DataInputStream;  
3. import java.util.Arrays;  
4. import java.util.Comparator;  
5. //import java.util.Scanner;   
6. class DNA{  
7.     String value;  
8.     int level;  
9. }  
10. class DNAType implements Comparator<Object>{   
11.     public int compare(Object arg0, Object arg1){  
12.         DNA obj1 = (DNA) arg0;  
13.         DNA obj2 = (DNA) arg1;  
14.         return obj1.level - obj2.level;  
15.     }  
16. }  
17. public class Main {  
18.     public static void main(String[] args) throws Exception {  
19.         int i;  
20.         //Scanner cin = new Scanner(System.in);   
21.         DataInputStream cin = new DataInputStream(new BufferedInputStream(System.in));  
22.         //int col = cin.nextInt();   
23.         //int row = cin.nextInt();   
24.         //cin.nextLine();   
25.         String s = new String();  
26.         s = cin.readLine();  
27.         String n[] = s.split(" ");  
28.         int col = Integer.parseInt(n[0]);  
29.         int row = Integer.parseInt(n[1]);  
30.         DNA dna[] = new DNA[row];  
31.         for(i = 0;i < row;++ i){  
32.             String line = new String();  
33.             //line = cin.nextLine();   
34.             line = cin.readLine();  
35.             dna[i] = new DNA();  
36.             dna[i].value = line;  
37.             dna[i].level = getLevel(line);  
38.         }  
39.         DNAType comp = new DNAType();  
40.         Arrays.sort(dna,comp);  
41.         for(i = 0;i < row;++ i){  
42.             System.out.println(dna[i].value);  
43.         }  
44.     }  
45.     private static int getLevel(String line) {  
46.         int i,j,t = 0;  
47.         for(i = 0;i < line.length();++ i){  
48.             for(j = i + 1;j < line.length();++ j){  
49.                 if(line.charAt(i) > line.charAt(j)){  
50.                     ++ t;  
51.                 }  
52.             }  
53.         }  
54.         return t;  
55.     }  
56. }