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|
package part_01
import (
"os"
"strconv"
"strings"
)
const USE_SAMPLE = false
type handType int
const (
HIGH_CARD handType = iota
PAIR
TWO_PAIR
THREE_OF_A_KIND
FULL_HOUSE
FOUR_OF_A_KIND
FIVE_OF_A_KIND
)
func (h handType) String() string {
return [...]string{"HIGH_CARD", "PAIR", "TWO_PAIR", "THREE_OF_A_KIND", "FULL_HOUSE", "FOUR_OF_A_KIND", "FIVE_OF_A_KIND"}[h]
}
type cardType int
const (
TWO cardType = iota
THREE
FOUR
FIVE
SIX
SEVEN
EIGHT
NINE
TEN
JACK
QUEEN
KING
ACE
)
func (c cardType) String() string {
return [...]string{"TWO", "THREE", "FOUR", "FIVE", "SIX", "SEVEN", "EIGHT", "NINE", "TEN", "JACK", "QUEEN", "KING", "ACE"}[c]
}
type hand struct {
strength handType
cards []cardType
bet int
}
/**
* Tried:
* - 252489894 (too high)
* - 229176554 (too low)
* - 200253108 (too low)
*/
func Solve() {
var filePath string
if USE_SAMPLE {
filePath = "../_input/day_07_part_01_sample.txt"
} else {
filePath = "../_input/day_07.txt"
}
contents, err := os.ReadFile(filePath)
if err != nil {
panic(err)
}
lines := strings.Split(string(contents), "\r\n")
var hands []hand
for _, line := range lines {
if line == "" {
continue
}
hands = append(hands, parseLine(line))
}
mappedByStrength := mapByStrength(hands)
sortedByHighest := make(map[handType][]hand)
for _, strength := range []handType{HIGH_CARD, PAIR, TWO_PAIR, THREE_OF_A_KIND, FULL_HOUSE, FOUR_OF_A_KIND, FIVE_OF_A_KIND} {
if _, ok := mappedByStrength[strength]; !ok {
continue
}
toBeSorted := mappedByStrength[strength]
sortedByHighest[strength] = sortByHighest(toBeSorted)
}
flattened := flatten(sortedByHighest)
answer := calculateWinnings(flattened)
println("Answer: ", answer)
}
func parseLine(line string) hand {
parts := strings.Split(line, " ")
unparsedCards := strings.Split(parts[0], "")
cards := parseCards(unparsedCards)
strength := calculateStrength(cards)
bet, err := strconv.Atoi(parts[1])
if err != nil {
panic(err)
}
return hand{
strength,
cards,
bet,
}
}
func parseCards(unparsedCards []string) []cardType {
var cards []cardType
for _, card := range unparsedCards {
switch card {
case "2":
cards = append(cards, TWO)
case "3":
cards = append(cards, THREE)
case "4":
cards = append(cards, FOUR)
case "5":
cards = append(cards, FIVE)
case "6":
cards = append(cards, SIX)
case "7":
cards = append(cards, SEVEN)
case "8":
cards = append(cards, EIGHT)
case "9":
cards = append(cards, NINE)
case "T":
cards = append(cards, TEN)
case "J":
cards = append(cards, JACK)
case "Q":
cards = append(cards, QUEEN)
case "K":
cards = append(cards, KING)
case "A":
cards = append(cards, ACE)
}
}
return cards
}
func calculateStrength(cards []cardType) handType {
strength := map[cardType]int{}
for _, card := range cards {
if _, ok := strength[card]; !ok {
strength[card] = 0
}
strength[card]++
}
var pairs int
var hasThreeOfAKind bool
for _, count := range strength {
if count == 5 {
return FIVE_OF_A_KIND
}
if count == 4 {
return FOUR_OF_A_KIND
}
if count == 3 {
hasThreeOfAKind = true
}
if count == 2 {
pairs++
}
}
if hasThreeOfAKind && pairs == 1 {
return FULL_HOUSE
}
if hasThreeOfAKind {
return THREE_OF_A_KIND
}
if pairs == 2 {
return TWO_PAIR
}
if pairs == 1 {
return PAIR
}
return HIGH_CARD
}
func mapByStrength(hands []hand) map[handType][]hand {
handsByStrength := make(map[handType][]hand)
for _, hand := range hands {
handsByStrength[hand.strength] = append(handsByStrength[hand.strength], hand)
}
return handsByStrength
}
// low to high
func sortByHighest(hands []hand) []hand {
var partition = func(arr []hand, low, high int) ([]hand, int) {
pivot := arr[high]
index := low
for i := low; i < high; i++ {
// Always 5 cards
for j := 0; j < 5; j++ {
if arr[i].cards[j] < pivot.cards[j] {
arr[i], arr[index] = arr[index], arr[i]
index++
break
}
if arr[i].cards[j] != pivot.cards[j] {
break
}
}
}
arr[high], arr[index] = arr[index], arr[high]
return arr, index
}
var quickSort func(arr []hand, low, high int) []hand
quickSort = func(arr []hand, low, high int) []hand {
if low < high {
arr, pivot := partition(arr, low, high)
quickSort(arr, low, pivot-1)
quickSort(arr, pivot+1, high)
}
return arr
}
hands = quickSort(hands, 0, len(hands)-1)
return hands
}
func flatten(hands map[handType][]hand) []hand {
var flat []hand
for _, handType := range []handType{HIGH_CARD, PAIR, TWO_PAIR, THREE_OF_A_KIND, FULL_HOUSE, FOUR_OF_A_KIND, FIVE_OF_A_KIND} {
flat = append(flat, hands[handType]...)
}
return flat
}
func calculateWinnings(hands []hand) int {
var winnings int
for i, hand := range hands {
earned := hand.bet * (i + 1)
winnings += earned
println("hand ", i, ": { strength: ", hand.strength.String(), ", cards: [", hand.cards[0], hand.cards[1], hand.cards[2], hand.cards[3], hand.cards[4], "], earned: ", earned, " }")
}
return winnings
}
|
