DNA Sorting
| Time Limit: 1000MS | Memory Limit: 10000K | |
| Total Submissions: 95209 | Accepted: 38311 |
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
C/C++代码
#include <stdio.h>
#include <string.h>
#include <stdlib.h> struct Str{
char str[];
int inversions;
}data[]; int inversionNumber(char s[]) { int len = strlen(s);
int result = ;
int A = , C = , G = ;
int i = len - ;
for(; i >= ; i--)
switch (s[i]) {
case 'A':
A++;
break;
case 'C':
result += A;
C++;
break;
case 'G':
result = result + A + C;
G++;
break;
case 'T':
result = result + A + C + G;
break;
}
return result;
} int cmp(const void * a, const void * b) { struct Str* c = (struct Str *)a;
struct Str* d = (struct Str *)b;
return c->inversions - d->inversions; } int main(int argc, const char * argv[]) { int length, number;
int i;
scanf("%d%d", &length, &number); for (i = ; i < number; i ++) {
scanf("%s", data[i].str);
data[i].inversions = inversionNumber(data[i].str);
} qsort(data, number, sizeof(data[]), cmp); for (i = ; i < number; i ++) {
printf("%s\n", data[i].str);
} return ;
}