dfs_main_improved.go

func main() {
   n := NewNode(1)
   n.Left = NewNode(2)
   n.Right = NewNode(3)
   n.Left.Left = NewNode(4)
   n.Left.Right = NewNode(5)
   n.Right.Left = NewNode(6)
   n.Right.Right = NewNode(7)
   n.Right.Right.Left = NewNode(8)

   start := time.Now()
   DFRec(n)
   fmt.Printf("took %v\n", time.Now().Sub(start))

   start = time.Now()
   wg.Add(1)
   go DFRecImproved(n)
   wg.Wait()

   fmt.Printf("took %v\n", time.Now().Sub(start))
}