View Code of Problem 48

#include <iostream>
#include <cstdio>
#include <iomanip>
using namespace std;
int main(){
    int n,a[999],b[999];
    double sum=0.0;
    cin>>n;
    a[0]=2,b[0]=1;
    for(int i=1;i<=n;i++){
        a[i]=a[i-1]+b[i-1];
        b[i]=a[i-1];
        sum+=a[i-1]*1.0/b[i-1]*1.0;
    }
    cout<<fixed<<setprecision(6)<<sum<<endl;
    return 0;
}