Big update: Adding all advent of codes to same repo

AdventOfCode2020/day23/LinkedList.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"fmt"
+)
+
+type CustomLinkedList struct {
+	head   *CustomListNode
+	length int64
+}
+
+type CustomListNode struct {
+	payload int64
+	next    *CustomListNode
+}
+
+func (l *CustomLinkedList) prepend(n *CustomListNode) {
+	second := l.head
+	l.head = n
+	l.head.next = second
+	l.length++
+}
+
+func (l *CustomLinkedList) append(n *CustomListNode) {
+
+	if l.head == nil {
+		l.head = n
+	} else {
+		node := l.head
+		for node.next != nil {
+			node = node.next
+		}
+		node.next = n
+	}
+	l.length++
+}
+
+func (l *CustomLinkedList) appendNextTo(n *CustomListNode, pointer *CustomListNode) {
+	node := l.head
+	for node != nil {
+		if node == pointer {
+			next := node.next
+			node.next = n
+			n.next = next
+			l.length++
+			break
+		}
+		node = node.next
+	}
+}
+
+func main() {
+
+	linkedList := CustomLinkedList{}
+	linkedList.append(&CustomListNode{payload: 10})
+
+	node1 := &CustomListNode{payload: 1}
+	node2 := &CustomListNode{payload: 2}
+	node3 := &CustomListNode{payload: 3}
+
+	linkedList.append(node1)
+	linkedList.append(node2)
+	linkedList.append(node3)
+
+	linkedList.appendNextTo(&CustomListNode{payload: 69}, node2)
+
+	node := linkedList.head
+	for node != nil {
+		fmt.Println(node.payload)
+		node = node.next
+	}
+
+	fmt.Println("Length: ", linkedList.length)
+
+}

AdventOfCode2020/day23/go.mod

@@ -0,0 +1,3 @@
+module main
+
+go 1.16