dfs_improved.go

var wg sync.WaitGroup

func DFRecImproved(n *Node){
   if n == nil {
      return
   }
   wg.Add(1)
   go DFRecImproved(n.Left)
   n.Process()
   wg.Add(1)
   go DFRecImproved(n.Right)
   wg.Done()
}