View Code of Problem 48

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