答题

 主要就是

#include<iostream>

using namespace std;

float calculate(float x,float i,int n){
    float rate=1+i,ratio=1;
    while(n--){
        ratio=ratio*rate;
    }
    ratio=1/ratio;
    return x*ratio;
}

int main() {
    int n;
    float rate,x,result=0;
    cin>>n>>rate;
    for(int i=0;i<=n;i++){
        cin>>x;
        result+= calculate(x,rate,i);
    }
    cout<<result;
}