View Code of Problem 71

#include<stdio.h>
main(){
	int n,i,a=1,b=2,t;
	double sum;
	sum=0.00;
	scanf("%d",&n);
	for(i=1;i<=n;i++){
		sum=(double)b/a+sum;
		t=a+b;
		a=b;
		b=t;
	}
	printf("%.2lf",sum);
}