（POJ 1007）DNA Sorting

 

DNA Sorting

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. 

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 (0 < 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''. Since two strings can be equally sorted, then output them according to the orginal order.

Sample Input

10 6

AACATGAAGG

TTTTGGCCAA

TTTGGCCAAA

GATCAGATTT

CCCGGGGGGA

ATCGATGCAT

 

Sample Output

 

CCCGGGGGGA

AACATGAAGG

GATCAGATTT

ATCGATGCAT

TTTTGGCCAA

TTTGGCCAAA

Source

East Central North America 1998

 

AC code：

1 #include<stdio.h> 2 #include<string.h> 3 int main() 4 { 5 int m,n,str[108]={0},i,j,s=0,k,temp; 6 char string[108][100],ss[58]; 7 scanf("%d %d",&n,&m); 8 for(k=0;k<m;k++) 9 {10 scanf("%s",string[k]);11 for(i=0;i<n-1;i++)12 for(j=i+1;j<n;j++)13 {14 if(string[k][i]>string[k][j])15 str[k]++;16 }17 }18 for(j=0;j<m-1;j++)19 for(i=0;i<m-1-j;i++)20 if(str[i]>str[i+1])21 {22 temp=str[i];23 str[i]=str[i+1];24 str[i+1]=temp;25 strcpy(ss,string[i]);26 strcpy(string[i],string[i+1]);27 strcpy(string[i+1],ss);28 }29 for(i=0;i<m;i++)30 printf("%s/n",string[i],str[i]);31 getch();32 33 return 0;34 }