View Code of Problem 48

#include<stdio.h>
int main(void)
{
	int n,i;double f1=2,f2=1,f3,sum=0;
	scanf("%d",&n); 
	for(i=0;i<n;i++)
	{
	    sum=sum+f1/f2;
	    f3=f1+f2;
	    f2=f1;
	    f1=f3;
	}
	printf("%.6f",sum);
	return 0;
}