链接：http://acm.hdu.edu.cn/showproblem.php?pid=1379
DNA Sorting
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4034 Accepted Submission(s): 1765
Problem Description
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.
This problem contains multiple test cases!
The first line of a multiple input is an integer N, then a blank line followed by N input blocks. Each input block is in the format indicated in the problem description. There is a blank line between input blocks.
The output format consists of N output blocks. There is a blank line between output blocks.
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.
This problem contains multiple test cases!
The first line of a multiple input is an integer N, then a blank line followed by N input blocks. Each input block is in the format indicated in the problem description. There is a blank line between input blocks.
The output format consists of N output blocks. There is a blank line between output blocks.
Input
The first line contains two integers: a positive integer n (0 < n <= 50) giving the length of the strings; and a positive integer m (1 < m <= 100) giving the number of strings. These are followed by m lines, each containing a string of length n.
Output
Output the list of input strings, arranged from ``most sorted'' to ``least sorted''. If two or more strings are equally sorted, list them in the same order they are in the input file.
Sample Input
1
10 6
AACATGAAGG
TTTTGGCCAA
TTTGGCCAAA
GATCAGATTT
CCCGGGGGGA
ATCGATGCAT
Sample Output
CCCGGGGGGA
AACATGAAGG
GATCAGATTT
ATCGATGCAT
TTTTGGCCAA
TTTGGCCAAA
#include<stdio.h>
#define N 200
int main()
{
int len,n,i,j,h;
struct dna{
char str[N];
int number;
}a[N],t;
scanf("%d%d",&len,&n);
for(i=0;i<n;i++)
{
scanf("%s",a[i].str);
a[i].number=0;
}
for(i=0;i<n;i++)
{
for(j=0;j<len;j++)
{
for(h=j;h<len;h++)
if(a[i].str[h]<a[i].str[j])
a[i].number++;
}
}
for(i=0;i<n;i++)
{
for(j=0;j<n-1;j++)
if(a[j].number>a[j+1].number)
{
t=a[j];
a[j]=a[j+1];
a[j+1]=t;
}
}
for(i=0;i<n;i++)
printf("%s
",a[i].str);
return 0;
}
主要意思就是判断逆序数，从小到大排序，用结构体可以解决，另外，逆序数有可能相同，需要用稳定排序