View Code of Problem 71

#include <stdio.h>
#include <stdlib.h>
int main(){
	int i,n;
	double a=1.0,b=2.0;
	scanf("%d",&n);
	double t,sum=0.0;
	for(i=0;i<n;i++){
		sum=sum+b/a;
		t=b;
		b=t+a;
		a=t;
	} 
	printf("%.2lf\n",sum);
	return 0;
}