View Code of Problem 71

#include <iostream>
#include <iomanip>

using namespace std;

int main(){

    int n,a[1000]={0};
    double sum;
    cin>>n;
    a[0]=1;a[1]=2;
    if(n>1){
        for(int i=2;i<=n;i++){
        a[i]=a[i-1]+a[i-2];
        }
    }
    for(int i=0;i<n;i++){
        sum+=(double)a[i+1]/a[i];
        }

        cout<<fixed<<setprecision(2)<<sum<<endl;
    



    return 0;

}