HDU 1379 DNA sorting(求逆序数)

　　　　　　　　　　　　　　　DNA Sorting

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.

 

 

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

 

此题傻暴力求逆序数即可，我用的归并排序求。

 

代码：

 1 #include<cstdio>

 2 #include<cstring>

 3 #include<malloc.h>

 4 #include<algorithm>

 5 using namespace std;

 6 

 7 int ans;

 8 

 9 struct str

10 {

11     char s[105];

12     char sort_s[105];

13     int Num;

14 };

15 

16 bool cmp(struct str a,struct str b)

17 {

18     return a.Num<b.Num;

19 }

20 

21 void MergeArray(char a[],int L,int Mid,int R,char temp[])

22 {

23     int k=0;

24     int i=L,j=Mid+1;

25     int m=Mid,n=R;

26     while(i<=m&&j<=n)

27     {

28         if(a[i]<=a[j])

29         temp[k++]=a[i++];

30         else

31         {

32       　　  temp[k++]=a[j++];

33       　　  ans+=m-i+1;

34         }

35     }

36     while(i<=m)

37     temp[k++]=a[i++];

38     while(j<=n)

39     temp[k++]=a[j++];

40     for(i=0;i<k;i++)

41     a[L+i]=temp[i];

42 }

43 

44 void MergeSort(char a[],int L,int R,char temp[])

45 {

46     if(L<R)

47     {

48         int Mid=(L+R)/2;

49         MergeSort(a,L,Mid,temp);

50         MergeSort(a,Mid+1,R,temp);

51         MergeArray(a,L,Mid,R,temp);

52     }

53 }

54 

55 int main()

56 {

57     struct str S[55];

58     int i,m,n,t;

59     scanf("%d",&t);

60     while(t--)

61     {

62         scanf("%d%d",&m,&n);

63         for(i=0;i<n;i++)

64         scanf("%s",S[i].s);

65         for(i=0;i<n;i++)    

66         {

67             ans=0;

68             int len=strlen(S[i].s);

69             strcpy(S[i].sort_s,S[i].s);

70             char *p=(char*)malloc(sizeof(char)*(len+1));

71             MergeSort(S[i].sort_s,0,len-1,p);

72             S[i].Num=ans;

73             free(p);

74         }

75         sort(S,S+n,cmp);

76         for(i=0;i<n;i++)

77         printf("%s\n",S[i].s);

78     }

79     return 0;

80 }