HDU 5003 Osu!（水题）

Osu!

Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u

Submit Status Practice HDU 5003

Description

Osu! is a famous music game that attracts a lot of people. In osu!, there is a performance scoring system, which evaluates your performance. Each song you have played will have a score. And the system will sort all you scores in descending order. After that, the i-th song scored a _i will add 0.95^(i-1)*a _i to your total score. 

Now you are given the task to write a calculator for this system.

 

Input

The first line contains an integer T, denoting the number of the test cases. 

For each test case, the first line contains an integer n, denoting the number of songs you have played. The second line contains n integers a₁, a ₂, ..., a _n separated by a single space, denoting the score of each song. 

T<=20, n<=50, 1<=a _i<=500.

 

Output

For each test case, output one line for the answer. 

Your answers will be considered correct if its absolute error is smaller than 1e-5.

 

Sample Input

 12530 478 

 

Sample Output

 984.1000000000 

 

#include<iostream>#include<algorithm>#include<stdio.h>#include<string.h>#include<stdlib.h>using namespace std;double a[1001];int n;int cmp(const void *a,const void *b){     return *(double *)b > *(double *)a ? 1 : -1;}int main(){    int T;    scanf("%d",&T);    while(T--)    {        scanf("%d",&n);        for(int i=0;i<n;i++)        {            scanf("%lf",&a[i]);        }        qsort(a,n,sizeof(a[0]),cmp);        double sum = a[0];        double h = 0.95;        for(int i=1;i<n;i++)        {            sum += h * a[i];            h = h * 0.95;        }        printf("%.10lf\n",sum);    }    return 0;}