解题思路：水题，不多说。
1 #include<cstdio> 2 #include<cstring> 3 #include<algorithm> 4 #include<cmath> 5 using namespace std; 6 double A[505]; 7 8 int cmp(int x, int y) 9 { 10 return x > y; 11 } 12 13 int main() 14 { 15 int n, t; 16 scanf("%d", &t); 17 while(t--) 18 { 19 scanf("%d", &n); 20 double sum = 0; 21 for(int i = 1; i <= n; i++) 22 { 23 scanf("%lf", &A[i]); 24 //sum += A[i]; 25 } 26 sort(A+1, A+1+n, cmp); 27 for(int i = 1; i <= n; i++) sum += pow(0.95, (i-1))*A[i]; 28 printf("%.10lf ", sum); 29 } 30 return 0; 31 }