View Code of Problem 48

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