Java程序练习-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.

输入
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.
输出
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.
样例输入
10 6
AACATGAAGG
TTTTGGCCAA
TTTGGCCAAA
GATCAGATTT
CCCGGGGGGA
ATCGATGCAT
样例输出
CCCGGGGGGA
AACATGAAGG
GATCAGATTT
ATCGATGCAT
TTTTGGCCAA
TTTGGCCAAA

参考代码

import java.io.BufferedInputStream;import java.io.DataInputStream;import java.util.Arrays;import java.util.Comparator;//import java.util.Scanner;class DNA{String value;int level;}class DNAType implements Comparator<Object>{     public int compare(Object arg0, Object arg1){    DNA obj1 = (DNA) arg0;    DNA obj2 = (DNA) arg1;        return obj1.level - obj2.level;    }}public class Main {public static void main(String[] args) throws Exception {int i;//Scanner cin = new Scanner(System.in);DataInputStream cin = new DataInputStream(new BufferedInputStream(System.in));//int col = cin.nextInt();//int row = cin.nextInt();//cin.nextLine();String s = new String();s = cin.readLine();String n[] = s.split(" ");int col = Integer.parseInt(n[0]);int row = Integer.parseInt(n[1]);DNA dna[] = new DNA[row];for(i = 0;i < row;++ i){String line = new String();//line = cin.nextLine();line = cin.readLine();dna[i] = new DNA();dna[i].value = line;dna[i].level = getLevel(line);}DNAType comp = new DNAType();Arrays.sort(dna,comp);for(i = 0;i < row;++ i){System.out.println(dna[i].value);}}private static int getLevel(String line) {int i,j,t = 0;for(i = 0;i < line.length();++ i){for(j = i + 1;j < line.length();++ j){if(line.charAt(i) > line.charAt(j)){++ t;}}}return t;}}