2023/go/day02/day02.go

   1 package day02
   2
   3 import (
   4         "fmt"
   5         "regexp"
   6         _ "strconv"
   7         "strings"
   8
   9         "adventofcode2023/utils"
  10 )
  11
  12 type Set struct {
  13         Red   int
  14         Blue  int
  15         Green int
  16 }
  17
  18 type Game struct {
  19         ID    int
  20         Sets []Set
  21 }
  22
  23 func Part1(input string) int {
  24         sum := 0
  25         games := []Game{}
  26
  27         lines := strings.Split(input, "\n")
  28         for _, line := range lines {
  29                 game, err := parseGame(line)
  30                 if err != nil {
  31                         fmt.Println("Error:", err)
  32                         return -1
  33                 }
  34                 // Print the parsed Game struct
  35                 fmt.Printf("Parsed Game: %+v\n", game)
  36                 games = append(games, game)
  37         }
  38         for _, game := range games {
  39                 result := true
  40                 for _, set := range game.Sets {
  41                         if set.Red > 12 || set.Green > 13 || set.Blue > 14 {
  42                                 result = false
  43                         }
  44                 }
  45                 if result == true {
  46                         sum += game.ID
  47                 }
  48         }
  49         return sum
  50 }
  51
  52 func Part2(input string) int {
  53         sum := 0
  54         games := []Game{}
  55
  56         lines := strings.Split(input, "\n")
  57         for _, line := range lines {
  58                 game, err := parseGame(line)
  59                 if err != nil {
  60                         fmt.Println("Error:", err)
  61                         return -1
  62                 }
  63                 // Print the parsed Game struct
  64                 fmt.Printf("Parsed Game: %+v\n", game)
  65                 games = append(games, game)
  66         }
  67         for _, game := range games {
  68                 maxRed := 0
  69                 maxBlue := 0
  70                 maxGreen := 0
  71                 for _, set := range game.Sets {
  72                         if set.Red > maxRed {
  73                                 maxRed = set.Red
  74                         }
  75                         if set.Blue > maxBlue {
  76                                 maxBlue = set.Blue
  77                         }
  78                         if set.Green > maxGreen {
  79                                 maxGreen = set.Green
  80                         }
  81                 }
  82                 sum +=  maxRed * maxBlue * maxGreen
  83         }
  84         return sum
  85 }
  86
  87 func parseGame(input string) (Game, error) {
  88         var game Game
  89
  90         // Extract ID
  91         reID := regexp.MustCompile(`Game (\d+):(.*)`)
  92         matchID := reID.FindStringSubmatch(input)
  93         if len(matchID) != 3 {
  94                 return game, fmt.Errorf("unable to extract game ID")
  95         }
  96         game.ID = utils.MustAtoi(matchID[1])
  97         setsString := strings.Split(matchID[2], ";")
  98         for _, setString := range setsString {
  99                 var set Set
 100                 // Extract colors and quantities
 101                 reColors := regexp.MustCompile(`(\d+) (\w+)`)
 102                 matches := reColors.FindAllStringSubmatch(setString, -1)
 103                 for _, match := range matches {
 104                         color := strings.ToLower(match[2])
 105                         switch color {
 106                         case "red":
 107                                 set.Red = utils.MustAtoi(match[1])
 108                         case "blue":
 109                                 set.Blue = utils.MustAtoi(match[1])
 110                         case "green":
 111                                 set.Green = utils.MustAtoi(match[1])
 112                         default:
 113                                 return game, fmt.Errorf("unknown color: %s", color)
 114                         }
 115                 }
 116                 game.Sets = append(game.Sets, set)
 117         }
 118         return game, nil
 119 }