algo

type ComplexListNode struct {
	Val     int
	Next    *ComplexListNode
	Sibling *ComplexListNode
}

type DoublyTreeNode struct {
	Data       Object
	Father     *DoublyTreeNode
	LeftChild  *DoublyTreeNode
	RightChild *DoublyTreeNode
}

type ListNode struct {
	Val  int
	Next *ListNode
}

type Object interface{}

type Stack struct {
	// contains filtered or unexported fields
}

type TreeNode struct {
	Data       Object
	LeftChild  *TreeNode
	RightChild *TreeNode
}