AoC Day 7, Parts 1 and 2 (Solved)

2023/07/code.go

@@ -0,0 +1,285 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+	"unicode"
+
+	"github.com/jpillora/puzzler/harness/aoc"
+)
+
+func main() {
+	aoc.Harness(run)
+}
+
+type Hand struct {
+	Cards string
+	Bid   int
+}
+
+func getCardPower(card rune) int {
+	if unicode.IsNumber(card) {
+		i, _ := strconv.Atoi(string(card))
+		return i
+	}
+
+	if card == 'T' {
+		return 10
+	}
+
+	if card == 'J' {
+		return 11
+	}
+
+	if card == 'Q' {
+		return 12
+	}
+
+	if card == 'K' {
+		return 13
+	}
+
+	if card == 'A' {
+		return 14
+	}
+
+	panic(fmt.Sprintf("Bad card %v", card))
+}
+
+func getCardPowerJokerRules(card rune) int {
+	if unicode.IsNumber(card) {
+		i, _ := strconv.Atoi(string(card))
+		return i
+	}
+
+	if card == 'T' {
+		return 10
+	}
+
+	if card == 'J' {
+		return 0
+	}
+
+	if card == 'Q' {
+		return 12
+	}
+
+	if card == 'K' {
+		return 13
+	}
+
+	if card == 'A' {
+		return 14
+	}
+
+	panic(fmt.Sprintf("Bad card %v", card))
+}
+
+func getHandTypeRanking(hand Hand) int {
+	cardUniq := make(map[string]int)
+
+	for _, c := range strings.Split(hand.Cards, "") {
+		if _, ok := cardUniq[c]; !ok {
+			cardUniq[c] = 0
+		}
+		cardUniq[c] += 1
+	}
+
+	if len(cardUniq) == 1 {
+		// Full house, top priority
+		return 7
+	}
+
+	if len(cardUniq) == 2 {
+		// Either four of a kind or full house
+		for _, x := range cardUniq {
+			if x == 4 || x == 1 {
+				// Four of a kind
+				return 6
+			} else {
+				// Must be full house
+				return 5
+			}
+		}
+	}
+
+	if len(cardUniq) == 3 {
+		// Either three of a kind or two pair
+		for _, x := range cardUniq {
+			if x == 3 {
+				// Three of a kind
+				return 4
+			} else if x == 2 {
+				// Two pair
+				return 3
+			}
+		}
+	}
+
+	if len(cardUniq) == 4 {
+		// Must be one pair
+		return 2
+	}
+
+	// Must be high card
+	return 1
+}
+func getHandTypeRankingJokerRules(hand Hand) int {
+	cardUniq := make(map[string]int)
+
+	jokerCount := 0
+	for _, c := range strings.Split(hand.Cards, "") {
+		if _, ok := cardUniq[c]; !ok {
+			cardUniq[c] = 0
+		}
+		cardUniq[c] += 1
+
+		if c == "J" {
+			jokerCount += 1
+		}
+	}
+
+	if len(cardUniq) == 1 {
+		// Full house, top priority
+		return 7
+	}
+
+	if len(cardUniq) == 2 {
+		// Either four of a kind or full house
+		for _, x := range cardUniq {
+			if x == 4 || x == 1 {
+				// Four of a kind
+				if jokerCount == 4 || jokerCount == 1 {
+					// Can be converted to 5oac
+					return 7
+				}
+				return 6
+			} else {
+				// Must be full house
+				if jokerCount == 3 || jokerCount == 2 {
+					// Can be converted to 5oac
+					return 7
+				}
+				return 5
+			}
+		}
+	}
+
+	if len(cardUniq) == 3 {
+		// Either three of a kind or two pair
+		for _, x := range cardUniq {
+			if x == 3 {
+				// Three of a kind
+				if jokerCount == 1 || jokerCount == 3 {
+					// Can be converted to 4oac
+					return 6
+				}
+				return 4
+			} else if x == 2 {
+				// Two pair
+				if jokerCount == 2 {
+					// Can be converted to 4oac
+					return 6
+				} else if jokerCount == 1 {
+					// Can be converted to full house
+					return 5
+				}
+				return 3
+			}
+		}
+	}
+
+	if len(cardUniq) == 4 {
+		// Must be one pair
+		if jokerCount == 2 || jokerCount == 1 {
+			// Can be converted to 3oac
+			return 4
+		}
+		return 2
+	}
+
+	// Must be high card
+	if jokerCount == 1 {
+		// Converted to one pair
+		return 2
+	}
+	return 1
+}
+
+// on code change, run will be executed 4 times:
+// 1. with: false (part1), and example input
+// 2. with: true (part2), and example input
+// 3. with: false (part1), and user input
+// 4. with: true (part2), and user input
+// the return value of each run is printed to stdout
+func run(part2 bool, input string) any {
+	hands := make([]Hand, 0)
+
+	for _, line := range strings.Split(input, "\n") {
+		if line == "" {
+			continue
+		}
+
+		lspl := strings.Split(line, " ")
+		bid, _ := strconv.Atoi(lspl[1])
+
+		hands = append(hands, Hand{lspl[0], bid})
+	}
+
+	if part2 {
+		sort.SliceStable(hands, func(i, j int) bool {
+			// First compare rank
+			hRank1 := getHandTypeRankingJokerRules(hands[i])
+			hRank2 := getHandTypeRankingJokerRules(hands[j])
+
+			if hRank1 != hRank2 {
+				return hRank1 < hRank2
+			}
+
+			// Otherwise, compare cards
+			for k := 0; k < 5; k++ {
+				cRank1 := getCardPowerJokerRules(rune(hands[i].Cards[k]))
+				cRank2 := getCardPowerJokerRules(rune(hands[j].Cards[k]))
+
+				if cRank1 != cRank2 {
+					return cRank1 < cRank2
+				}
+			}
+
+			panic(fmt.Sprintf("Could not sort %v and %v", hands[i].Cards, hands[j].Cards))
+		})
+
+	} else {
+		sort.SliceStable(hands, func(i, j int) bool {
+			// First compare rank
+			hRank1 := getHandTypeRanking(hands[i])
+			hRank2 := getHandTypeRanking(hands[j])
+
+			if hRank1 != hRank2 {
+				return hRank1 < hRank2
+			}
+
+			// Otherwise, compare cards
+			for k := 0; k < 5; k++ {
+				cRank1 := getCardPower(rune(hands[i].Cards[k]))
+				cRank2 := getCardPower(rune(hands[j].Cards[k]))
+
+				if cRank1 != cRank2 {
+					return cRank1 < cRank2
+				}
+			}
+
+			panic(fmt.Sprintf("Could not sort %v and %v", hands[i].Cards, hands[j].Cards))
+		})
+	}
+	// solve part 1 here
+
+	winnings := 0
+	for i, hand := range hands {
+		winnings += (i + 1) * hand.Bid
+	}
+
+	return winnings
+}