View Code of Problem 48

#include<iostream>
#include<iomanip>
#include<string>
#include<algorithm>
#include<math.h>
using namespace std;
double fsi(double n) {
	if (n == 1 || n == 2) {
		return n;
	}
	return fsi(n - 1) + fsi(n - 2);
}
int main() {
	int n;
	double sum = 0;
	cin >> n;
	for (int i = 1; i<n-1; i++) {
		sum =sum + fsi(i + 1) / fsi(i);
	}
	cout << fixed << setprecision(6) << sum << endl;
	return 0;
}