Linked Lists in Golang

doubly_linked_list.go

package main

import "fmt"

type Node struct {
	Value any
	Next *Node
	Prev *Node
}

type linkedList struct {
	head *Node
	tail *Node
	size int
}

func (ll *linkedList) Append(value any) {
	n := Node{value, nil, nil}
	if ll.head == nil {
		ll.head = &n
		ll.tail = &n
		ll.size++
		return
	}
	
	n.Prev = ll.tail
	ll.tail.Next = &n
	ll.tail = &n
	ll.size++
}

func (ll *linkedList) Prepend(value any) {
	n := Node{value, nil, nil}
	if ll.head == nil {
		ll.head = &n
		ll.tail = &n
		ll.size++
		return
	}

	n.Next = ll.head
	ll.head.Prev = &n
	ll.head = &n
	ll.size++
}

func (ll *linkedList) InsertAt(value any, pos int) {
	if pos < 0 || pos > ll.size {
		return
	}

	if pos == 0 {
		ll.Prepend(value)
		return
	}

	var currNode, prevNode *Node
	var i int
	currNode = ll.head
	for i < pos {
		prevNode = currNode
		currNode = currNode.Next
		i++
	}

	n := Node{value, currNode, prevNode}
	currNode.Prev = &n
	prevNode.Next = &n
	ll.size++
}

func (ll *linkedList) DeleteAt(pos int) {
	if pos < 0 || pos > ll.size {
		return
	}

	if pos == 0 {
		ll.head = ll.head.Next
		ll.head.Prev = nil
		ll.size--
		return
	}

	var currNode, prevNode *Node
	var i int
	currNode = ll.head
	for i < pos {
		prevNode = currNode
		currNode = currNode.Next
		i++
	}

	prevNode.Next = currNode.Next
	currNode.Prev = prevNode
	ll.size--
}

func (ll *linkedList) Print() {
	n := ll.head
	var i int
	for n.Next != nil {
		fmt.Println(n.Value, " at ", i)
		n = n.Next
		i++
	}
	fmt.Println(n.Value, " at ", i)
}

func main() {
	l := linkedList{}
	l.Append("test")
	l.Append("hello")
	l.Prepend("yolo")
	l.InsertAt("t", 0)
	l.InsertAt("b", 1)
	l.DeleteAt(0)
	l.DeleteAt(1)
	l.Print()
}

singly_linked_list.go

package main

import "fmt"

type Node struct {
	Value any
	Next *Node
}

type linkedList struct {
	head *Node
	size int
}

func (ll *linkedList) Append(value any) {
	n := Node{value, nil}
	if ll.head == nil {
		ll.head = &n
		ll.size++
		return
	}

	h := ll.head
	for h.Next != nil {
		h = h.Next
	}

	h.Next = &n
	ll.size++
}

func (ll *linkedList) Prepend(value any) {
	n := Node{value, nil}
	if ll.head == nil {
		ll.head = &n
		ll.size++
		return
	}

	n.Next = ll.head
	ll.head = &n
	ll.size++
}

func (ll *linkedList) InsertAt(value any, pos int) {
	if pos < 0 || pos > ll.size {
		return
	}

	if pos == 0 {
		ll.Prepend(value)
		return
	}

	var currNode, prevNode *Node
	var i int
	currNode = ll.head
	for i < pos {
		prevNode = currNode
		currNode = currNode.Next
		i++
	}

	n := Node{value, currNode}
	prevNode.Next = &n
	ll.size++
}

func (ll *linkedList) DeleteAt(pos int) {
	if pos < 0 || pos > ll.size {
		return
	}

	if pos == 0 {
		ll.head = ll.head.Next
		ll.size--
		return
	}

	var currNode, prevNode *Node
	var i int
	currNode = ll.head
	for i < pos {
		prevNode = currNode
		currNode = currNode.Next
		i++
	}

	prevNode.Next = currNode.Next
	ll.size--
}

func (ll *linkedList) Print() {
	n := ll.head
	var i int
	for n.Next != nil {
		fmt.Println(n.Value, " at ", i)
		n = n.Next
		i++
	}
	fmt.Println(n.Value, " at ", i)
}

func main() {
	l := linkedList{}
	l.Append("test")
	l.Append("hello")
	l.Prepend("yolo")
	l.InsertAt("t", 0)
	l.InsertAt("b", 1)
	l.DeleteAt(0)
	l.DeleteAt(1)
	l.Print()
}