From 2e59d1bdc0282965bbd1879144c60577a0034195 Mon Sep 17 00:00:00 2001
From: Karl Spickermann <karliosos65@googlemail.com>
Date: Fri, 24 Dec 2021 14:09:03 +0100
Subject: [PATCH] Day23

---
 src/day23/day23.go | 47 +++++++++++++++++++++++-----------------------
 1 file changed, 23 insertions(+), 24 deletions(-)

diff --git a/src/day23/day23.go b/src/day23/day23.go
index 8865c88..3e0cd36 100644
--- a/src/day23/day23.go
+++ b/src/day23/day23.go
@@ -9,7 +9,6 @@ import (
 type board struct {
 	corridor [11]rune
 	rooms    [4][4]rune
-	energy   int
 }
 
 var costs = map[rune]int{
@@ -31,21 +30,18 @@ var enterableCorridorPos = [7]int{0, 1, 3, 5, 7, 9, 10}
 func main() {
 	playBoard := board{
 		[11]rune{'.', '.', '.', '.', '.', '.', '.', '.', '.', '.', '.'},
-		[4][4]rune{{'D', 'D', 'D', 'B'}, {'D', 'C', 'B', 'A'}, {'C', 'B', 'A', 'A'}, {'B', 'A', 'C', 'C'}}, 0}
-	currentBoards := []board{}
-	endBoards := []board{}
-	currentBoards = append(currentBoards, playBoard)
+		[4][4]rune{{'D', 'D', 'D', 'B'}, {'D', 'C', 'B', 'A'}, {'C', 'B', 'A', 'A'}, {'B', 'A', 'C', 'C'}}}
+	currentBoards := make(map[board]int)
+	endBoards := make(map[board]int)
+	currentBoards[playBoard] = 0
 	for len(currentBoards) > 0 {
 		step(&currentBoards, &endBoards)
-		fmt.Println(len(currentBoards))
-		fmt.Println(len(endBoards))
 	}
-	fmt.Println(len(endBoards))
 	minEnergy := 9999999
-	for _, endBoard := range endBoards {
-		if checkWinner(endBoard) && endBoard.energy < minEnergy {
-			if minEnergy > endBoard.energy {
-				minEnergy = endBoard.energy
+	for endBoard, energy := range endBoards {
+		if checkWinner(endBoard) && energy < minEnergy {
+			if minEnergy > energy {
+				minEnergy = energy
 			}
 		}
 	}
@@ -63,25 +59,28 @@ func checkWinner(board board) bool {
 	return true
 }
 
-func step(currentBoards *[]board, endBoards *[]board) {
-	var newBoards []board
-	for _, selectedBoard := range *currentBoards {
+func step(currentBoards *map[board]int, endBoards *map[board]int) {
+	for selectedBoard, selectedEnergy := range *currentBoards {
+		delete(*currentBoards, selectedBoard)
 		possibleMoves := getPossibleMoves(selectedBoard)
 		if len(possibleMoves) == 0 {
-			*endBoards = append(*endBoards, selectedBoard)
+			if (*endBoards)[selectedBoard] == 0 || selectedEnergy < (*endBoards)[selectedBoard] {
+				(*endBoards)[selectedBoard] = selectedEnergy
+			}
 		}
 		for start, targets := range possibleMoves {
 			for _, target := range targets {
-				tmpNewBoard := useMove(selectedBoard, [2][2]int{start, target})
-				newBoards = append(newBoards, tmpNewBoard)
+				tmpNewBoard, tmpNewErnergy := useMove(selectedBoard, [2][2]int{start, target}, selectedEnergy)
+				if (*currentBoards)[tmpNewBoard] == 0 || tmpNewErnergy < (*currentBoards)[tmpNewBoard] {
+					(*currentBoards)[tmpNewBoard] = tmpNewErnergy
+				}
 			}
 		}
 	}
-	*currentBoards = newBoards
 	return
 }
 
-func useMove(board board, move [2][2]int) board {
+func useMove(board board, move [2][2]int, energy int) (board, int) {
 	//Remove moved Amphoid
 	var amphoidType rune
 	if move[0][0] == 0 {
@@ -102,14 +101,14 @@ func useMove(board board, move [2][2]int) board {
 	//Calculate cost
 	traveledDistance := 0
 	if move[0][0] == 0 {
-		traveledDistance += Abs(move[0][1] - (move[1][0]*2 + 2))
+		traveledDistance += Abs(move[0][1] - ((move[1][0]-1)*2 + 2))
 		traveledDistance += move[1][1] + 1
 	} else {
-		traveledDistance += Abs(move[1][1] - (move[0][0]*2 + 2))
+		traveledDistance += Abs(move[1][1] - ((move[0][0]-1)*2 + 2))
 		traveledDistance += move[0][1] + 1
 	}
-	board.energy += costs[amphoidType] * (traveledDistance)
-	return board
+	energy += costs[amphoidType] * (traveledDistance)
+	return board, energy
 }
 
 func getPossibleMoves(board board) map[[2]int][][2]int {