View Code of Problem 48

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