hdu 5003 水题

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define MAX 57

using namespace std;

int t , n;
int a[MAX];

bool cmp ( int a , int b )
{
    return a > b;
}

int main  ( )
{
    scanf ( "%d" , &t );
    while ( t-- )
    {
        double sum = 0;
        scanf ( "%d" , &n );
        for ( int i = 1 ; i <= n ; i++ ) scanf ( "%d" , &a[i] );
        sort ( a+1 , a+n+1 , cmp );
        for ( int i = 1 ; i <= n ; i++ ) 
           sum += pow ( 0.95 , i-1 ) *a[i]; 
        printf ( "%.9lf\n" , sum );
    }
}