day02

2023/go/day02/day02.go

@@ -0,0 +1,119 @@
+package day02
+
+import (
+	"fmt"
+	"regexp"
+	_ "strconv"
+	"strings"
+
+	"adventofcode2023/utils"
+)
+
+type Set struct {
+	Red   int
+	Blue  int
+	Green int
+}
+
+type Game struct {
+	ID    int
+	Sets []Set
+}
+
+func Part1(input string) int {
+	sum := 0
+	games := []Game{}
+
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		game, err := parseGame(line)
+		if err != nil {
+			fmt.Println("Error:", err)
+			return -1
+		}
+		// Print the parsed Game struct
+		fmt.Printf("Parsed Game: %+v\n", game)
+		games = append(games, game)
+	}
+	for _, game := range games {
+		result := true
+		for _, set := range game.Sets {
+			if set.Red > 12 || set.Green > 13 || set.Blue > 14 {
+				result = false
+			}
+		}
+		if result == true {
+			sum += game.ID
+		}
+	}
+	return sum
+}
+
+func Part2(input string) int {
+	sum := 0
+	games := []Game{}
+
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		game, err := parseGame(line)
+		if err != nil {
+			fmt.Println("Error:", err)
+			return -1
+		}
+		// Print the parsed Game struct
+		fmt.Printf("Parsed Game: %+v\n", game)
+		games = append(games, game)
+	}
+	for _, game := range games {
+		maxRed := 0
+		maxBlue := 0
+		maxGreen := 0
+		for _, set := range game.Sets {
+			if set.Red > maxRed {
+				maxRed = set.Red
+			}
+			if set.Blue > maxBlue {
+				maxBlue = set.Blue
+			}
+			if set.Green > maxGreen {
+				maxGreen = set.Green
+			}		
+		}
+		sum +=  maxRed * maxBlue * maxGreen
+	}
+	return sum
+}
+
+func parseGame(input string) (Game, error) {
+	var game Game
+
+	// Extract ID
+	reID := regexp.MustCompile(`Game (\d+):(.*)`)
+	matchID := reID.FindStringSubmatch(input)
+	if len(matchID) != 3 {
+		return game, fmt.Errorf("unable to extract game ID")
+	}
+	game.ID = utils.MustAtoi(matchID[1])
+	setsString := strings.Split(matchID[2], ";")
+	for _, setString := range setsString {
+		var set Set
+		// Extract colors and quantities
+		reColors := regexp.MustCompile(`(\d+) (\w+)`)
+		matches := reColors.FindAllStringSubmatch(setString, -1)
+		for _, match := range matches {
+			color := strings.ToLower(match[2])
+			switch color {
+			case "red":
+				set.Red = utils.MustAtoi(match[1])
+			case "blue":
+				set.Blue = utils.MustAtoi(match[1])
+			case "green":
+				set.Green = utils.MustAtoi(match[1])
+			default:
+				return game, fmt.Errorf("unknown color: %s", color)
+			}
+		}
+		game.Sets = append(game.Sets, set)
+	}
+	return game, nil
+}