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
#include<iostream> #include<cstdlib> //#include<fstream> using namespace std; //ifstream cin("poj.txt"); //ofstream cout("poj.out"); struct node { int num; char a[55]; }dna[110]; int n,m; int cal(char *s,int n) { int i,tot=0; int a[4]={0}; for (i=n-1;i>=0;i--) { switch(s[i]) { case 'A': a[1]++; a[2]++; a[3]++; break; case 'C': a[2]++; a[3]++; tot+=a[1]; break; case 'G': a[3]++; tot+=a[2]; break; case 'T': tot+=a[3]; } } return tot; } int cmp(const void *a,const void *b) { return (*(node *)a).num-(*(node *)b).num; } int main() { int i; cin>>n>>m; for (i=0;i<m;i++) { cin>>dna[i].a; dna[i].num=cal(dna[i].a,n); } qsort(dna,m,sizeof(node),cmp); for (i=0;i<m;i++) cout<<dna[i].a<<endl; return 0; }