View Code of Problem 48

#include <stdio.h>
#include <string.h>
int main(){
	int n;
	scanf("%d",&n);
	double f1=2,f2=1,t,sum=0;
	for(int i=1;i<=n;i++){
		sum+=f1/f2;
		t=f1;
		f1=t+f2;
		f2=t;
	}
	printf("%.6lf\n",sum);
	return 0;
}