day 7 part 2

angristan · Dec 7, 2023 · f7aacb8 · f7aacb8
1 parent 3385e41
commit f7aacb8
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Showing 2 changed files with 435 additions and 28 deletions.
diff --git a/07/07.go b/07/07.go
@@ -10,24 +10,33 @@ import (
 )
 
 func main() {
-	input := utils.ParseInput("/Users/stanislaslange/advent-of-code-2023/07/input.txt")
+	input := utils.ParseInput("input.txt")
 
 	parsedInput := ConvertRawInputToInput(input)
 	part1Score := parsedInput.ComputeTotalPoints()
 	fmt.Printf("Part 1: %d\n", part1Score)
+
+	parsedInputV2 := ConvertRawInputToInputV2(input)
+	for i := range parsedInputV2.Hands {
+		parsedInputV2.Hands[i].ComputeAndAssignHandType()
+		parsedInputV2.Hands[i].JokerMode()
+	}
+	parsedInputV2.SortHands()
+	part2Score := parsedInputV2.ComputeTotalPoints()
+	fmt.Printf("Part 2: %d\n", part2Score)
 }
 
-type Hand struct {
+type HandV1 struct {
 	Cards string
 	Bid   int
 }
 
-type Input struct {
-	Hands []Hand
+type InputV1 struct {
+	Hands []HandV1
 }
 
-func ConvertRawInputToInput(rawInput []string) Input {
-	input := Input{}
+func ConvertRawInputToInput(rawInput []string) InputV1 {
+	input := InputV1{}
 
 	for _, line := range rawInput {
 		splitLine := strings.Split(line, " ")
@@ -37,7 +46,7 @@ func ConvertRawInputToInput(rawInput []string) Input {
 			panic(err)
 		}
 
-		hand := Hand{
+		hand := HandV1{
 			Cards: cards,
 			Bid:   bid,
 		}
@@ -48,7 +57,7 @@ func ConvertRawInputToInput(rawInput []string) Input {
 	return input
 }
 
-func (input Input) SortHands() {
+func (input InputV1) SortHands() {
 	sort.Slice(input.Hands, func(i, j int) bool {
 		occurrencesI := input.Hands[i].Occurrences()
 		occurrencesJ := input.Hands[j].Occurrences()
@@ -106,7 +115,7 @@ func (input Input) SortHands() {
 	})
 }
 
-func (hand Hand) Occurrences() []int {
+func (hand HandV1) Occurrences() []int {
 	occurrences := make([]int, 5)
 
 	for _, card := range hand.Cards {
@@ -129,13 +138,200 @@ func (hand Hand) Occurrences() []int {
 	return occurrences
 }
 
-func (input Input) ComputeTotalPoints() int {
+func (input InputV1) ComputeTotalPoints() int {
 	input.SortHands()
 
-	for _, hand := range input.Hands {
-		fmt.Printf("%s %d\n", hand.Cards, hand.Bid)
+	totalPoints := 0
+	for i, hand := range input.Hands {
+		totalPoints += hand.Bid * (i + 1)
+	}
+
+	return totalPoints
+}
+
+/*
+==============================
+	Part 2
+==============================
+*/
+
+type HandType int
+
+const (
+	HighCard HandType = iota
+	OnePair
+	TwoPair
+	ThreeOfAKind
+	FullHouse
+	FourOfAKind
+	FiveOfAKind
+)
+
+type HandV2 struct {
+	Cards    string
+	Bid      int
+	HandType HandType
+}
+
+type InputV2 struct {
+	Hands []HandV2
+}
+
+func ConvertRawInputToInputV2(rawInput []string) InputV2 {
+	input := InputV2{}
+
+	for _, line := range rawInput {
+		splitLine := strings.Split(line, " ")
+		cards := splitLine[0]
+		bid, err := strconv.Atoi(splitLine[1])
+		if err != nil {
+			panic(err)
+		}
+
+		hand := HandV2{
+			Cards: cards,
+			Bid:   bid,
+		}
+
+		input.Hands = append(input.Hands, hand)
+	}
+
+	return input
+}
+
+func (hand HandV2) ComputeOcurrences() []int {
+	occurrences := make([]int, 5)
+
+	for _, card := range hand.Cards {
+		count := strings.Count(hand.Cards, string(card))
+
+		if count == 0 {
+			continue
+		}
+		indexCount := count - 1
+
+		if ok := occurrences[indexCount]; ok == 0 {
+			occurrences[indexCount] = 1
+		} else {
+			occurrences[indexCount]++
+		}
+
+		hand.Cards = strings.ReplaceAll(hand.Cards, string(card), "")
+	}
+
+	return occurrences
+}
+
+func (hand *HandV2) ComputeAndAssignHandType() {
+	occurrences := hand.ComputeOcurrences()
+
+	if occurrences[5-1] == 1 {
+		hand.HandType = FiveOfAKind
+		return
 	}
 
+	if occurrences[4-1] == 1 {
+		hand.HandType = FourOfAKind
+		return
+	}
+
+	if occurrences[3-1] == 1 && occurrences[2-1] == 1 {
+		hand.HandType = FullHouse
+		return
+	}
+
+	if occurrences[3-1] == 1 {
+		hand.HandType = ThreeOfAKind
+		return
+	}
+
+	if occurrences[2-1] == 2 {
+		hand.HandType = TwoPair
+		return
+	}
+
+	if occurrences[2-1] == 1 {
+		hand.HandType = OnePair
+		return
+	}
+
+	hand.HandType = HighCard
+}
+
+func (hand *HandV2) JokerMode() {
+	JCount := strings.Count(hand.Cards, "J")
+
+	if JCount == 0 {
+		return
+	}
+
+	for i := 0; i < JCount; i++ {
+		switch hand.HandType {
+		case FiveOfAKind:
+			return
+		case FourOfAKind:
+			hand.HandType = FiveOfAKind
+			if strings.Count(hand.Cards, "J") == 4 {
+				return
+			}
+		case FullHouse:
+			hand.HandType = FourOfAKind
+		case ThreeOfAKind:
+			hand.HandType = FourOfAKind
+			if strings.Count(hand.Cards, "J") == 3 {
+				return
+			}
+		case TwoPair:
+			hand.HandType = FullHouse
+		case OnePair:
+			hand.HandType = ThreeOfAKind
+			if strings.Count(hand.Cards, "J") == 2 {
+				return
+			}
+		case HighCard:
+			hand.HandType = OnePair
+		}
+	}
+}
+
+func (input InputV2) SortHands() {
+	sort.Slice(input.Hands, func(i, j int) bool {
+		if input.Hands[i].HandType != input.Hands[j].HandType {
+			return input.Hands[i].HandType < input.Hands[j].HandType
+		}
+
+		strengths := map[string]int{
+			"A": 13,
+			"K": 12,
+			"Q": 11,
+			"T": 10,
+			"9": 9,
+			"8": 8,
+			"7": 7,
+			"6": 6,
+			"5": 5,
+			"4": 4,
+			"3": 3,
+			"2": 2,
+			"J": 1,
+		}
+
+		for cardIndex := 0; cardIndex < 5; cardIndex++ {
+			cardJ := string(input.Hands[j].Cards[cardIndex])
+			cardI := string(input.Hands[i].Cards[cardIndex])
+
+			if strengths[cardI] != strengths[cardJ] {
+				return strengths[cardI] < strengths[cardJ]
+			}
+		}
+
+		return true
+	})
+}
+
+func (input InputV2) ComputeTotalPoints() int {
+	input.SortHands()
+
 	totalPoints := 0
 	for i, hand := range input.Hands {
 		totalPoints += hand.Bid * (i + 1)