http://poj.org/problem?id=1007
代码:
/*DNA Sorting Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 56496 Accepted: 22147 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> using namespace std; const int maxinver = 10000; int getMinIndex(int [],int); int main(){ int n,m; cin>>n>>m; char p[100][50]; int inverArr[100]={0}; //得到字符数组p【】【】的逆序数 for(int i=0;i<m;i++){ int inver=0; for(int j=0;j<n;j++){ cin>>p[i][j]; } for(int j=0;j<n;j++){ for(int k=j+1;k<n;k++) if(p[i][j]>p[i][k]) inver++; inverArr[i]=inver; } } /*每次找到inverArr【】的一个最小值的下标i,然后把inverArr【i】的值设为一个最大值maxinver, 之后再次循环找到inverArr【】数组的次小值。。。*/ for(int i=0;i<m;i++){ int minIndex = getMinIndex(inverArr,m); inverArr[minIndex]= maxinver; for(int j=0;j<n;j++) cout<<p[minIndex][j]; cout<<endl; } return 0; } /*找到数组inver【】的最小值的下标*/ int getMinIndex(int inver[],int length){ int min = inver[0]; int k=0; for(int i=1;i<length;i++){ if(inver[i]<min){ min = inver[i]; k = i; } } return k; }