View Code of Problem 48

#include<stdio.h>
int main()
{
	int n;
  	scanf("%d",&n);
  	double a=1.0,b=2.0,t;
  	double sum=0;
  	for(int i=0;i<n;i++)
        {
        	sum=sum+b/a;
          	t=b;
          	b=a+b;
          	a=t;
        }
  	printf("%.6lf\n",sum);
  	return 0;
}