View Code of Problem 48

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