题目链接 http://poj.org/problem?id=1007
C++代码实现

#include<string>
#include<iostream>
using namespace std;
struct DNAdata	//定义结构体
{char name[51];double sum;DNAdata(){sum = 0;}
};
void swapDNA(DNAdata *a, DNAdata *b)
{DNAdata tempDNA;tempDNA = *a;*a = *b;*b = tempDNA;
}
int main()
{size_t n, m;	//dna序列位数n，m个dna序列cin >> n >> m;DNAdata dna[101];char temp;size_t i,j,k;for(i = 0; i != m; ++i){for(j = 0; j != n; ++j) //输入1个dna的字符序列{cin >> dna[i].name[j];}for(j = 0; j != n; ++j) //对该序列进行求逆序数{temp = dna[i].name[j];for(k = j+1; k != n; ++k){if(temp>dna[i].name[k]){++dna[i].sum;}}}}for (i = 0; i != m; ++i)  //插入排序{for (j = i; j > 0 && dna[j-1].sum > dna[j].sum; --j)//每次的子列都是有序的，判断条件可写在for(内)，否则不可（这么做减少运行次数）//每次和有序数组最后一个比较，向前搜索，直到找到位置停止{swapDNA(&dna[j-1], &dna[j]);}}for (i = 0; i != m; ++i)  //输出排序后的dna序列{for(j = 0; j != n; ++j){cout << dna[i].name[j];}cout << endl;}return 0;
}

方法2

#include<string>
#include<iostream>
using namespace std;
struct DNAdata	//定义结构体
{char name[51];double sum;DNAdata(){sum = 0;}
};
void swapDNA(DNAdata *a, DNAdata *b)
{DNAdata tempDNA;tempDNA = *a;*a = *b;*b = tempDNA;
}
int main()
{size_t n, m;	//dna序列位数n，m个dna序列cin >> n >> m;DNAdata dna[101];char temp;size_t i,j,k;size_t A = 0, C = 0, G = 0;for(i = 0; i != m; ++i){for(j = 0; j != n; ++j) //输入1个dna的字符序列{cin >> dna[i].name[j];}for(int j = n-1; j >= 0; --j)	//从后往前计算逆序数{switch(dna[i].name[j]){case 'A':++A;break;case 'C':++C;dna[i].sum += A;break;case 'G':++G;dna[i].sum += A + C;break;case 'T':dna[i].sum += A + C + G;break;default:break;}}A = 0;	//为下一个计算，清零C = 0;G = 0;}for (i = 0; i != m; ++i)	//插入排序{for (j = i; j > 0 && dna[j-1].sum > dna[j].sum; --j)//每次的子列都是有序的，判断条件可写在for(内)，否则不可（这么做减少运行次数）//每次和有序数组最后一个比较，向前搜索，直到找到位置停止{swapDNA(&dna[j-1], &dna[j]);}}for (i = 0; i != m; ++i)  //输出排序后的dna序列{for(j = 0; j != n; ++j){cout << dna[i].name[j];}cout << endl;//cout << " " << dna[i].sum << endl;}return 0;
}