1 files changed, 138 insertions, 0 deletions
diff --git a/go/2023/internal/day_02/part_01/part_01.go b/go/2023/internal/day_02/part_01/part_01.go
new file mode 100644
index 0000000..9efe20f
--- /dev/null
+++ b/go/2023/internal/day_02/part_01/part_01.go
@@ -0,0 +1,138 @@
+package part_01
+
+import (
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type cubes struct {
+	red   int
+	blue  int
+	green int
+}
+
+func Solve() {
+	contents, err := os.ReadFile("../_input/day_02.txt")
+	if err != nil {
+		panic(err)
+	}
+
+	lines := strings.Split(string(contents), "\n")
+	possibleGameIds := processLines(lines)
+
+	println(accumulate(possibleGameIds))
+}
+
+func processLines(lines []string) []int {
+	var possibleGames []int
+
+	maxCubes := cubes{red: 12, blue: 14, green: 13}
+
+	for _, line := range lines {
+		if line == "" || line == "\n" {
+			continue
+		}
+
+		shownCubes := convertLineToCubes(line)
+
+		isPossible := isPossibleGame(shownCubes, maxCubes)
+		if isPossible {
+			gameId := getGameId(line)
+			possibleGames = append(possibleGames, gameId)
+		}
+	}
+
+	return possibleGames
+}
+
+func convertLineToCubes(line string) []cubes {
+	var shownCubes []cubes
+
+	redRegex := regexp.MustCompile(`(\d+) red`)
+	blueRegex := regexp.MustCompile(`(\d+) blue`)
+	greenRegex := regexp.MustCompile(`(\d+) green`)
+
+	for _, round := range strings.Split(line, ";") {
+		var cubes cubes
+
+		redMatches := redRegex.FindStringSubmatch(round)
+		if redMatches != nil {
+			red, err := strconv.Atoi(redMatches[1])
+			if err != nil {
+				panic("Could not convert red to int: " + redMatches[1])
+			} else {
+				cubes.red = red
+			}
+		}
+
+		blueMatches := blueRegex.FindStringSubmatch(round)
+		if blueMatches != nil {
+			blue, err := strconv.Atoi(blueMatches[1])
+			if err != nil {
+				panic("Could not convert green to int: " + blueMatches[1])
+			} else {
+				cubes.blue = blue
+			}
+		}
+
+		greenMatches := greenRegex.FindStringSubmatch(round)
+		if greenMatches != nil {
+			green, err := strconv.Atoi(greenMatches[1])
+			if err != nil {
+				panic("Could not convert green to int: " + greenMatches[1])
+			} else {
+				cubes.green = green
+			}
+		}
+
+		shownCubes = append(shownCubes, cubes)
+	}
+
+	return shownCubes
+}
+
+func isPossibleGame(shownCubes []cubes, maxCubes cubes) bool {
+	for _, cubes := range shownCubes {
+		if cubes.red > maxCubes.red {
+			return false
+		}
+
+		if cubes.blue > maxCubes.blue {
+			return false
+		}
+
+		if cubes.green > maxCubes.green {
+			return false
+		}
+	}
+
+	return true
+}
+
+func getGameId(line string) int {
+	regex := regexp.MustCompile(`^Game (\d+):`)
+	matches := regex.FindStringSubmatch(line)
+	if matches == nil || len(matches) < 2 {
+		println(matches)
+		panic("No game id found in line: '" + line + "'")
+	}
+
+	gameId, err := strconv.Atoi(matches[1])
+	if err != nil {
+		panic("Could not convert game id to int: " + matches[1])
+	}
+
+	return gameId
+}
+
+func accumulate(gameIds []int) int {
+	var acc int
+
+	for _, gameId := range gameIds {
+		acc += gameId
+	}
+
+	return acc
+}