Advent-of-Code-2023/day7/daySevel.go

152 lines
2.9 KiB
Go

package day7
import (
"fmt"
"log"
"os"
"slices"
"strconv"
"strings"
)
func Run() int {
fmt.Print("hello day 7")
filename := "day7/input"
input := ReadFile(filename)
slices.SortFunc(input, CompareHands)
// log.Printf("read the input %+v\n", input)
for _, hand := range input {
// fmt.Printf("%+v\n", hand)
fmt.Printf("%+s\t\t%d\n", hand.Cards, hand.HandType)
}
slices.SortFunc([]int{}, func(a int, b int) int { return 0 })
result := 0
for i, hand := range input {
result += (i+1) * hand.Bid
}
return result
}
type HandType int
const (
HighCard = iota
OnePair
TwoPair
ThreeKind
FullHouse
FourKind
FiveKind
)
type Hand struct {
Cards string
Grouped map[rune]int
HandType HandType
Bid int
}
// cmp(a, b) should return a negative number when a < b, a positive number when
// a > b and zero when a == b.
const values string = "J23456789TQKA"
func CompareHands(a Hand, b Hand) int {
if a.HandType != b.HandType {
return int(a.HandType) - int(b.HandType)
}
return compareString(a.Cards, b.Cards)
}
func compareString(a string, b string) int {
for i := 0; i < len(a); i++ {
if a[i] == b[i] {
continue
}
aVal := strings.IndexRune(values, rune(a[i]))
bVal := strings.IndexRune(values, rune(b[i]))
return aVal - bVal
}
return 0
}
func GetHandType(groupped map[rune]int) HandType {
var handType HandType
jokerSize, found := groupped['J']
if !found {
jokerSize = 0
}
sizes := make([]int, 0, len(groupped))
for card, size := range groupped {
if card != 'J' {
sizes = append(sizes, size)
}
}
slices.SortFunc(sizes, func (a, b int) int { return b - a })
var highest int
if len(sizes) == 0 {
highest = jokerSize
} else {
highest = sizes[0] + jokerSize
}
if highest == 5 {
return FiveKind
}
if highest == 4 {
return FourKind
}
other := sizes[1]
if highest == 3 {
if other == 2 {
return FullHouse
}
return ThreeKind
}
if highest == 2 {
if other == 2 {
return TwoPair
}
return OnePair
}
// log.Printf("calc type for %+v.\nsizes: %+v;\n %d", groupped, sizes, handType)
return handType
}
func ReadFile(filename string) []Hand {
bytes, err := os.ReadFile(filename)
if err != nil {
panic(fmt.Sprintln("error reading file : ", filename))
}
text := string(bytes)
lines := strings.Split(text, "\n")
linesLen := len(lines)
result := make([]Hand, 0, linesLen)
for _, line := range lines {
log.Println("reading in line : ", line)
if line == "" {
continue
}
firstSplit := strings.Fields(line)
cards := firstSplit[0]
bidStr := firstSplit[1]
bid, err := strconv.Atoi(bidStr)
if err != nil {
panic(fmt.Sprintln("error getting bid from : ", bidStr))
}
groupped := make(map[rune]int, 0)
for _, card := range cards {
groupped[card] += 1
}
hand := Hand{
Cards: cards,
Grouped: groupped,
Bid: bid,
HandType: GetHandType(groupped),
}
result = append(result, hand)
}
return result
}