View Code of Problem 48

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