[Go] Linked List 구현

package datastruct

import (
    "fmt"
)

type LinkedList struct {
    Head *Node
    Tail *Node
    Size int
}

type Node struct {
    Data any
    Next *Node
}

func NewLinkedList() *LinkedList {
    return &LinkedList{
        Head: nil,
        Tail: nil,
        Size: 0,
    }
}

func newNode(value any) *Node {
    return &Node{
        Data: value,
        Next: nil,
    }
}

func (list *LinkedList) Lpush(value any) {
    node := newNode(value)

    if list.Head == nil {
        list.Head = node
        list.Tail = node

    } else {
        node.Next = list.Head
        list.Head = node
    }
    list.Size += 1
}

func (list *LinkedList) Rpush(value any) {
    node := newNode(value)

    if list.Tail == nil {
        list.Head = node
        list.Tail = node

    } else {
        list.Tail.Next = node
        list.Tail = node
    }
    list.Size += 1
}

func (list *LinkedList) ShowNodes() {
    if list.Size == 0 {
        fmt.Println("LinkedList is empty")

    } else {
        node := list.Head
        res := fmt.Sprintf("%v → ", node.Data)

        for i := 1; i < list.Size; i++ {
            node = node.Next
            res += fmt.Sprintf("%v → ", node.Data)
        }
        fmt.Println(res)
    }
}

func (list *LinkedList) Lpop() *Node {
    if list.Size == 0 {
        return nil

    } else if list.Size == 1 {
        head := list.Head
        list.Head = nil
        list.Tail = nil
        list.Size -= 1
        return head

    } else {
        head := list.Head
        list.Head = head.Next
        list.Size -= 1
        return head
    }
}

func (list *LinkedList) Rpop() *Node {
    if list.Size == 0 {
        return nil

    } else if list.Size == 1 {
        tail := list.Tail
        list.Head = nil
        list.Tail = nil

        list.Size -= 1
        return tail

    } else {
        tail := list.Tail

        node := list.Head
        for i := 1; i < list.Size; i++ {
            node = node.Next
            if i == list.Size-2 {
                list.Tail = node
                list.Tail.Next = nil
            }
        }

        list.Size -= 1
        return tail
    }
}

func LinkedListMain() {
    linkedList := NewLinkedList()

    // lpush
    linkedList.Lpush(1)
    linkedList.Lpush(2)
    linkedList.Lpush(3)

    // rpush
    linkedList.Rpush(4)
    linkedList.Rpush(5)
    linkedList.Rpush(6)

    // show
    linkedList.ShowNodes()

    // lpop
    linkedList.Lpop()
    linkedList.Lpop()
    linkedList.ShowNodes()

    // rpop
    linkedList.Rpop()
    linkedList.Rpop()
    linkedList.ShowNodes()

    // pop
    linkedList.Lpop()
    linkedList.ShowNodes()
    linkedList.Rpop()
    linkedList.ShowNodes()

    // push
    linkedList.Rpush(4)
    linkedList.Rpush(5)
    linkedList.ShowNodes()

    // pop
    linkedList.Rpop()
    linkedList.Rpop()
    linkedList.ShowNodes()
}