day 2 part 1

day2/day2.go

@@ -0,0 +1,101 @@
+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
+	possible bool
+}
+
+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{}
+	possible := true
+	for _, v := range draws_splitted {
+		draw := Draw{}
+		draw.red, _ = strconv.Atoi(strings.Split(getColors(v, "red"), " ")[0])
+		draw.green, _ = strconv.Atoi(strings.Split(getColors(v, "green"), " ")[0])
+		draw.blue, _ = strconv.Atoi(strings.Split(getColors(v, "blue"), " ")[0])
+		if (draw.red > limits.red) || (draw.green > limits.green) || (draw.blue > limits.blue) {
+			possible = false
+		}
+		draws = append(draws, draw)
+	}
+
+	game := Game{
+		id:       id,
+		draws:    draws,
+		possible: possible,
+	}
+
+	// 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.possible {
+			games = append(games, game)
+			sum_ids += game.id
+		}
+	}
+
+	fmt.Println(sum_ids)
+
+}
+
+func main() {
+	input := readInput()
+	lines := strings.Split(input, "\n")
+	part1(lines)
+}

day2/example.txt

@@ -0,0 +1,5 @@
+Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green

go.work

@@ -0,0 +1 @@
+go 1.21.5