封装

type TreeNode struct {
    Left, Right *TreeNode
    Value       int
}

//值接收者和指针接收者和传参数类型没有什么区别
//如果要改变内容或内容比较大，建议用值接收者
func (root *TreeNode) traverse() {
    if root == nil {
        return
    }
    root.Left.traverse()
    fmt.Print(root.Value, " ")
    root.Right.traverse()
}

func createTreeNode(v int) *TreeNode {
    return &TreeNode{Value: v}
}

func main() {
    var root TreeNode
    root = TreeNode{Value: 3}
    root.Left = createTreeNode(4)
    root.Right = &TreeNode{Value: 5}
    root.Left.Right = createTreeNode(2)
    root.Right.Left = createTreeNode(8)
    root.traverse()
}

扩展已有类型

type TreeNode struct {
    Left, Right *TreeNode
    Value       int
}

//值接收者和指针接收者和传参数类型没有什么区别
//如果要改变内容或内容比较大，建议用值接收者
func (root *TreeNode) traverse() {
    if root == nil {
        return
    }
    root.Left.traverse()
    root.print()
    root.Right.traverse()
}
func (root *TreeNode) print() {
    fmt.Print(root.Value, " ")
}

type myTreeNode struct {
    node *TreeNode
}

func (myNode *myTreeNode) postOrder() {
    if myNode == nil || myNode.node == nil {
        return
    }
    left := myTreeNode{myNode.node.Left}
    right := myTreeNode{myNode.node.Right}
    left.postOrder()
    right.postOrder()
    myNode.node.print()

}

func createTreeNode(v int) *TreeNode {
    return &TreeNode{Value: v}
}

func main() {
    var root TreeNode
    root = TreeNode{Value: 3}
    root.Left = createTreeNode(4)
    root.Right = &TreeNode{Value: 5}
    root.Left.Right = createTreeNode(2)
    root.Right.Left = createTreeNode(8)
    root.traverse()
    fmt.Println()
    myroot := myTreeNode{&root}
    myroot.postOrder()
}