chore: add day 7

day07/example.txt

@@ -0,0 +1,5 @@
+32T3K 765
+T55J5 684
+KK677 28
+KTJJT 220
+QQQJA 483

day07/main.go

@@ -0,0 +1,260 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"sort"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Fprintln(os.Stderr, "Usage: day06 FILE")
+	}
+
+	input, err := os.Open(os.Args[1])
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+	}
+
+	scan := bufio.NewScanner(input)
+
+	score1, score2 := run(scan)
+
+	fmt.Println("score 1", score1)
+	fmt.Println("score 2", score2)
+}
+
+func run(scan *bufio.Scanner) (uint64, uint64) {
+	var game Game
+
+	for scan.Scan() {
+		var cards string
+		var bid int
+		_, err := fmt.Sscanf(scan.Text(), "%s %d", &cards, &bid)
+		if err != nil {
+			panic(err)
+		}
+
+		fmt.Println("cards", cards, "bid", bid)
+		game.plays = append(game.plays, Play{bid, []rune(cards), &game})
+	}
+
+	game.cardOrder = getOrder(1)
+	product1 := calcProduct(game)
+
+	game.cardOrder = getOrder(2)
+	product2 := calcProduct(game)
+
+	return product1, product2
+}
+
+var cardTypes1 = []rune{'A', 'K', 'Q', 'J', 'T', '9', '8', '7', '6', '5', '4', '3', '2'}
+var cardTypes2 = []rune{'A', 'K', 'Q', 'T', '9', '8', '7', '6', '5', '4', '3', '2', 'J'}
+
+func calcProduct(game Game) uint64 {
+	sort.Sort(game.plays)
+
+	var product uint64
+	for i, play := range game.plays {
+		rank := i + 1
+		fmt.Printf("play %d %s %d %s %x\n", rank, string(play.hand), play.bid, play.HandType(), play.HandStrength())
+		product += uint64(play.bid * rank)
+	}
+	return product
+}
+
+func getOrder(v int) map[rune]int {
+	cardTypes := cardTypes1
+	if v == 2 {
+		cardTypes = cardTypes2
+	}
+	cardOrder := make(map[rune]int, len(cardTypes))
+	for i, r := range cardTypes {
+		cardOrder[r] = len(cardTypes) - i
+	}
+	return cardOrder
+}
+
+type Game struct {
+	plays     Plays
+	cardOrder map[rune]int
+	wildCard  rune
+}
+
+type Play struct {
+	bid  int
+	hand Hand
+	game *Game
+}
+
+type Hand []rune
+
+func (h Play) HandType() string {
+	hc, _ := h.HighCard()
+	switch {
+	case h.IsFiveOfKind():
+		return "5K-" + string(hc)
+	case h.IsFourOfKind():
+		return "4K-" + string(hc)
+	case h.IsFullHouse():
+		return "FH-" + string(hc)
+	case h.IsThreeOfKind():
+		return "3K-" + string(hc)
+	case h.IsTwoPair():
+		return "2P-" + string(hc)
+	case h.IsOnePair():
+		return "1P-" + string(hc)
+	case h.IsHighCard():
+		return "HC-" + string(hc)
+	}
+	return "Uno"
+}
+
+func (h Play) HandStrength() int {
+	_, v := h.HighCard()
+	switch {
+	case h.IsFiveOfKind():
+		return 0x700000 | v
+	case h.IsFourOfKind():
+		return 0x600000 | v
+	case h.IsFullHouse():
+		return 0x500000 | v
+	case h.IsThreeOfKind():
+		return 0x400000 | v
+	case h.IsTwoPair():
+		return 0x300000 | v
+	case h.IsOnePair():
+		return 0x200000 | v
+	case h.IsHighCard():
+		return 0x100000 | v
+	}
+	return 0
+}
+
+func (h Play) IsFiveOfKind() bool {
+	_, _, _, _, has5 := h.game.hasSame(h.hand)
+	return has5
+}
+func (h Play) IsFourOfKind() bool {
+	_, _, _, has4, _ := h.game.hasSame(h.hand)
+	return has4
+}
+func (h Play) IsFullHouse() bool {
+	_, has2, has3, _, _ := h.game.hasSame(h.hand)
+	return has3 && has2
+}
+func (h Play) IsThreeOfKind() bool {
+	has1, _, has3, _, _ := h.game.hasSame(h.hand)
+	return has3 && has1
+}
+func (h Play) IsTwoPair() bool {
+	_, has2, has3, _, _ := h.game.hasSame(h.hand)
+	return !has3 && has2 && h.game.pairs(h.hand) == 2
+}
+func (h Play) IsOnePair() bool {
+	_, has2, has3, _, _ := h.game.hasSame(h.hand)
+	return !has3 && has2 && h.game.pairs(h.hand) == 1
+}
+func (h Play) IsHighCard() bool {
+	has1, has2, has3, has4, _ := h.game.hasSame(h.hand)
+	return has1 && !has2 && !has3 && !has4
+}
+func (h Play) HighCard() (rune, int) {
+	var i int
+	pairs := make(Pairs, 5)
+	cnt := h.game.Counts(h.hand)
+	for r, c := range cnt {
+		pairs[i].c = c
+		pairs[i].r = r
+		pairs[i].o = h.game.cardOrder[r]
+
+		i++
+	}
+
+	sort.Sort(sort.Reverse(pairs))
+
+	value := 0
+	for i, r := range h.hand {
+		if r == 0 {
+			continue
+		}
+
+		value |= h.game.cardOrder[r] << (4 * (4 - i))
+	}
+
+	return pairs[0].r, value
+}
+
+type Pairs []struct {
+	r rune
+	c int
+	o int
+}
+
+func (p Pairs) Len() int { return len(p) }
+func (p Pairs) Less(i, j int) bool {
+	if p[i].c == p[j].c {
+		return p[i].o < p[j].o
+	}
+	return p[i].c < p[j].c
+}
+func (p Pairs) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
+
+type Plays []Play
+
+func (p Plays) Len() int           { return len(p) }
+func (p Plays) Less(i, j int) bool { return p[i].HandStrength() < p[j].HandStrength() }
+func (p Plays) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (g *Game) Counts(cards []rune) map[rune]int {
+	m := make(map[rune]int, len(g.cardOrder))
+	for _, c := range cards {
+		m[c]++
+	}
+	if g.wildCard != 0 && m[g.wildCard] > 0 {
+		var maxK rune
+		var maxV int
+		for k, v := range m {
+			if k != g.wildCard && v > maxV {
+				maxK, maxV = k, v
+			}
+		}
+		if maxK != 0 {
+			m[maxK] += m[g.wildCard]
+			delete(m, g.wildCard)
+		}
+	}
+	return m
+}
+func (g *Game)hasSame(cards []rune) (has1, has2, has3, has4, has5 bool) {
+	cnt := g.Counts(cards)
+	for _, c := range cnt {
+		switch c {
+		case 1:
+			has1 = true
+
+		case 2:
+			has2 = true
+
+		case 3:
+			has3 = true
+
+		case 4:
+			has4 = true
+
+		case 5:
+			has5 = true
+		}
+	}
+	return
+}
+func (g *Game) pairs(cards []rune) int {
+	pairs := 0
+	for _, n := range g.Counts(cards) {
+		if n == 2 {
+			pairs++
+		}
+	}
+	return pairs
+}

day07/main_test.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"testing"
+
+	_ "embed"
+
+	"github.com/matryer/is"
+)
+
+// AKQJT98765432
+// dcba987654321
+
+//go:embed example.txt
+var example []byte
+
+//go:embed input.txt
+var input []byte
+
+func TestHands(t *testing.T) {
+	is := is.New(t)
+
+	var game Game
+	game.cardOrder = getOrder(1)
+
+	h := Play{0, []rune("AAA23"), &game}
+	is.Equal(h.HandType(), "3K-A")
+
+	h = Play{0, []rune("JJJJJ"), &game}
+	is.Equal(h.HandType(), "5K-J")
+	is.Equal(fmt.Sprintf("%x", h.HandStrength()), "7aaaaa")
+
+	h = Play{0, []rune("KKKKJ"), &game}
+	is.Equal(h.HandType(), "4K-K")
+	is.Equal(fmt.Sprintf("%x", h.HandStrength()), "6cccca")
+
+	h = Play{0, []rune("QQQJA"), &game}
+	is.Equal(h.HandType(), "3K-Q")
+	is.Equal(fmt.Sprintf("%x", h.HandStrength()), "4bbbad")
+
+}
+
+func TestPower(t *testing.T) {
+	for i := 1; i <= 13; i++ {
+		for j := 100; j < 800; j += 100 {
+			t.Log(i, j, i+j)
+		}
+	}
+}
+
+func TestExample(t *testing.T) {
+	is := is.New(t)
+	scan := bufio.NewScanner(bytes.NewReader(example))
+
+	score1, score2 := run(scan)
+	is.Equal(score1, uint64(6440))
+	is.Equal(score2, uint64(5905))
+}
+
+func TestSolution(t *testing.T) {
+	is := is.New(t)
+	scan := bufio.NewScanner(bytes.NewReader(input))
+
+	score1, score2 := run(scan)
+	t.Log("score1", score1)
+	is.Equal(score1, uint64(248559379))
+
+	t.Log("score2", score2)
+	is.Equal(score2, uint64(248761814))
+}