uva 10014

题意：单纯的数学推论题：自己动手吧

结果 ： (n + 1)a_{1 = na0 + an+1 - 2(nc1} + (n-1)c_{2 + (n-2)}c₃ + …… + c_n)

#include <iostream>#include <cstdio>#include <cstring>using namespace std;int main(){    int t,n;    double af,al,c,sum;    cin>>t;    while (t--)    {        cin>>n>>af>>al;        sum = 0 ;        for (int i = 0 ; i < n ; i++)        {            cin>>c;            sum += (n-i) * c;        }        printf("%0.2lf\n",(n*af + al - 2 * sum)/(n+1));        if (t)            printf("\n");    }    return 0;}