From 801d7f9a78e54a247575c15d7c7b13d74453e3a3 Mon Sep 17 00:00:00 2001
From: Luke Else <mail@luke-else.co.uk>
Date: Wed, 22 Dec 2021 01:02:12 +0000
Subject: [PATCH] day 21b incomplete

tried doing it, very close, I believe I have missed a very simple step or some edge case is not being run.

Value is currently way below what is expected So I either think one of the data structures is behaving badly, or I have missed a key point
---
 day21/21b/main.go             | 145 ++++++++++++++++++++++++++++++++++
 shared/LinkedListGameBoard.go |  39 +++++++++
 shared/Queue.go               |  29 +++++++
 3 files changed, 213 insertions(+)
 create mode 100644 day21/21b/main.go
 create mode 100644 shared/Queue.go

diff --git a/day21/21b/main.go b/day21/21b/main.go
new file mode 100644
index 0000000..ff5e998
--- /dev/null
+++ b/day21/21b/main.go
@@ -0,0 +1,145 @@
+package main
+
+import (
+	"AdventOfCode2021/shared"
+	"bufio"
+	"fmt"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+func main() {
+	//content := returnContent("../input")
+	content := returnContent("../testInput")
+
+	//Construct Game board... in reverse :) (Just makes it easier for stringing them together)
+	positions := make(map[int]*shared.GamePosition)
+	gameBoard := shared.GameBoard{
+		Start: &shared.GamePosition{
+			Position: 1,
+			Next:     nil,
+		},
+	}
+	positions[1] = gameBoard.Start
+	next := gameBoard.Start
+	var currentPosition *shared.GamePosition
+
+	for i := 10; i > 1; i-- {
+		currentPosition = new(shared.GamePosition)
+		currentPosition.Position = i
+		currentPosition.Next = next
+		next = currentPosition
+
+		positions[i] = currentPosition
+	}
+	gameBoard.Start.Next = currentPosition
+
+	//Add Players to the game
+	players := make(map[int]*shared.Player)
+	numPlayers := 0
+
+	for _, value := range *content {
+		newPlayer := shared.Player{
+			PlayerNum: value[0],
+			Score:     0,
+			Position:  positions[value[1]],
+		}
+		players[newPlayer.PlayerNum] = &newPlayer
+		numPlayers++
+	}
+
+	//Play the GAMEEEEEE
+	queue := shared.UniverseQueue{}
+	wins := make((map[int]int))
+	//Make the initial universe and add to queue
+
+	queue.Add(&shared.Universe{Players: players})
+
+	//Continue to process the universe
+
+	for {
+		current := queue.Pop()
+		if current == nil {
+			break
+		}
+
+		for _, p := range current.Players {
+			RecurseUniverse(current.Players, &queue, p.PlayerNum, wins)
+		}
+
+	}
+
+	fmt.Println(wins[1], wins[2])
+
+}
+
+func RecurseUniverse(players map[int]*shared.Player, queue *shared.UniverseQueue, player int, wins map[int]int) {
+	for d := 1; d <= 3; d++ {
+		//Create a new instance based on the current dice roll
+		alteredPlayer := Roll(*players[player], d)
+
+		if alteredPlayer.Score < 21 {
+			newUniverse := new(shared.Universe)
+
+			newPlayers := make(map[int]*shared.Player)
+			for _, p := range players {
+				newPlayer := *p
+				newPlayers[newPlayer.PlayerNum] = &newPlayer
+			}
+			newPlayers[player] = alteredPlayer
+			newUniverse.Players = newPlayers
+			queue.Add(newUniverse)
+		} else {
+			wins[player]++
+		}
+
+	}
+}
+
+func Roll(p shared.Player, diceVal int) *shared.Player {
+
+	//calculate where the position will be after n positions being moved
+	position := p.Position
+	for i := 0; i < diceVal; i++ {
+		position = position.Next
+	}
+
+	p.Position = position
+
+	p.Score += p.Position.Position
+
+	return &p
+
+}
+
+func returnContent(path string) *[][]int {
+	//read file and return it as an array of integers
+
+	file, err := os.Open(path)
+	var content [][]int
+
+	if err != nil {
+		fmt.Println("Unlucky, the file didn't open")
+		return &content
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+
+	regex, _ := regexp.Compile(`[0-9]+`)
+
+	for scanner.Scan() {
+
+		line := regex.FindAllString(scanner.Text(), 2)
+		nums := []int{}
+
+		for i := 0; i < len(line); i++ {
+			num, _ := strconv.Atoi(line[i])
+			nums = append(nums, num)
+		}
+		content = append(content, nums)
+	}
+
+	return &content
+}
diff --git a/shared/LinkedListGameBoard.go b/shared/LinkedListGameBoard.go
index 7fc1cef..7a4eef1 100644
--- a/shared/LinkedListGameBoard.go
+++ b/shared/LinkedListGameBoard.go
@@ -14,3 +14,42 @@ type Player struct {
 	Score     int
 	Position  *GamePosition
 }
+
+type Universe struct {
+	Players map[int]*Player
+}
+
+type QueueItem struct {
+	Universe *Universe
+	Next     *QueueItem
+}
+
+type UniverseQueue struct {
+	Head *QueueItem
+	Tail *QueueItem
+}
+
+func (q *UniverseQueue) Pop() (universe *Universe) {
+	universe = nil
+	if q.Head != nil {
+		universe = q.Head.Universe
+		q.Head = q.Head.Next
+		if q.Head == nil {
+			q.Tail = nil
+		}
+	}
+	return
+}
+
+func (q *UniverseQueue) Add(universe *Universe) {
+	newUniverse := new(QueueItem)
+	newUniverse.Universe = universe
+
+	if q.Tail != nil {
+		q.Tail.Next = newUniverse
+	} else {
+		q.Head = newUniverse
+	}
+
+	q.Tail = newUniverse
+}
diff --git a/shared/Queue.go b/shared/Queue.go
new file mode 100644
index 0000000..38a4c16
--- /dev/null
+++ b/shared/Queue.go
@@ -0,0 +1,29 @@
+package shared
+
+type Queue struct {
+	Head *Node
+	Tail *Node
+}
+
+func (q *Queue) Pop() (node *Node) {
+	node = nil
+	if q.Head != nil {
+		node = q.Head
+		q.Head = q.Head.Next
+		if q.Head == nil {
+			q.Tail = nil
+		}
+	}
+	return
+}
+
+func (q *Queue) Add(node *Node) {
+
+	if q.Tail != nil {
+		q.Tail.Next = node
+	} else {
+		q.Head = node
+	}
+
+	q.Tail = node
+}