View Code of Problem 48

#include<stdio.h>
main(){
	int n,i;
	double sum,a,b,t;
	a=1.0;
	b=2.0;
	scanf("%d",&n);
	sum=0.0;
	for(i=1;i<=n;i++){
		sum=sum+b/a;
		t=b;
		b=a+b;
		a=t;
	}
	printf("%.6lf",sum);
}