aoc2023/day-7/two.go

package main

import log "github.com/sirupsen/logrus"

// promote alters a hands kind based on joker rules
func promote(hand *hand) {
	m := matches(hand.cards)
	log.Debug(m)

	switch hand.kind() {
	case fiveofakind:
		break
	case fourofakind:
		hand._kind = fiveofakind
	case fullhouse:
		if m['J'] == 2 || m['J'] == 3 {
			hand._kind = fiveofakind
		}
		log.Debug(hand.cards, " was promoted to ", hand.kind())
	case threeofakind:
		if m['J'] == 1 || m['J'] == 3 {
			hand._kind = fourofakind
		}
		log.Debug(hand.cards, " was promoted to ", hand.kind())
	case twopair:
		if m['J'] == 1 {
			hand._kind = fullhouse
		} else if m['J'] == 2 {
			hand._kind = fourofakind
		}
		log.Debug(hand.cards, " was promoted to ", hand.kind())
	case onepair:
		if m['J'] == 1 || m['J'] == 2 {
			hand._kind = threeofakind
		}
		log.Debug(hand.cards, " was promoted to ", hand.kind())
	case highcard:
		hand._kind = onepair
		log.Debug(hand.cards, " was promoted to ", hand.kind())
	}
}

// two returns the sum of products of hand values by bids
// it uses new joker rules
func two(lines []string) (int, error) {
	for _, hand := range hands {
		if containsChar(hand.cards, "J") {
			promote(hand)
		}
	}

	strength := []rune{'A', 'K', 'Q', 'T', '9', '8', '7', '6', '5', '4', '3', '2', 'J'}
	log.Debug("strength: ", strength)
	sortByKindAndStrength(strength)

	sum := 0

	var debugNames = map[int]string{
		0: "highcard",
		1: "onepair",
		2: "twopair",
		3: "threeofakind",
		4: "fullhouse",
		5: "fourofakind",
		6: "fiveofakind",
	}

	for i, hand := range hands {
		log.Debug(hand.cards, ": ", hand.bid, " by ", i+1, " || ", debugNames[hand.kind()])
		sum += (i + 1) * hand.bid
	}

	return sum, nil
}