adventofcode2023/day02/day2.go

144 lines
2.5 KiB
Go

package main
import (
"fmt"
"io"
"os"
"regexp"
"strconv"
"strings"
)
type Limitations struct {
red int
blue int
green int
}
type Draw struct {
red int
blue int
green int
}
type Game struct {
id int
draws []Draw
meta Meta
}
type Meta struct {
possible bool
red_min int
green_min int
blue_min int
}
func readInput() string {
stdin, err := io.ReadAll(os.Stdin)
if err != nil {
panic(err)
}
str := string(stdin)
return str
}
func getColors(input string, color string) string {
rg := regexp.MustCompile(`[0-9]+ ` + regexp.QuoteMeta(color))
return rg.FindString(input)
}
func parseGameLine(line string, limits Limitations) Game {
splitted := strings.Split(line, ":")
draws_splitted := strings.Split(splitted[1], ";")
game_prefix := splitted[0]
id, _ := strconv.Atoi(strings.Split(game_prefix, " ")[1])
draws := []Draw{}
meta := Meta{}
red_min, green_min, blue_min := 0, 0, 0
meta.possible = true
for _, v := range draws_splitted {
red, _ := strconv.Atoi(strings.Split(getColors(v, "red"), " ")[0])
green, _ := strconv.Atoi(strings.Split(getColors(v, "green"), " ")[0])
blue, _ := strconv.Atoi(strings.Split(getColors(v, "blue"), " ")[0])
if (red > limits.red) || (green > limits.green) || (blue > limits.blue) {
meta.possible = false
}
if red_min < red {
red_min = red
}
if green_min < green {
green_min = green
}
if blue_min < blue {
blue_min = blue
}
draw := Draw{
red: red,
blue: blue,
green: green,
}
draws = append(draws, draw)
}
meta.blue_min = blue_min
meta.red_min = red_min
meta.green_min = green_min
game := Game{
id: id,
draws: draws,
meta: meta,
}
// fmt.Println(game)
return game
}
func part1(lines []string) {
limits := Limitations{
red: 12,
green: 13,
blue: 14,
}
var games []Game
sum_ids := 0
for _, l := range lines {
if len(l) == 0 {
continue
}
game := parseGameLine(l, limits)
if game.meta.possible {
games = append(games, game)
sum_ids += game.id
}
}
fmt.Println("Sum ids:", sum_ids)
}
func part2(lines []string) {
var games []Game
for _, l := range lines {
if len(l) == 0 {
continue
}
game := parseGameLine(l, Limitations{})
games = append(games, game)
}
sum := 0
for _, g := range games {
sum += (g.meta.red_min * g.meta.green_min * g.meta.blue_min)
}
fmt.Println(sum)
}
func main() {
input := readInput()
lines := strings.Split(input, "\n")
fmt.Println("---PART 1---")
part1(lines)
fmt.Println("---PART 2---")
part2(lines)
}