2023 Day 2

2023/day02/main.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	_ "embed"
+	"flag"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var input string
+
+func init() {
+	fileBytes, err := os.ReadFile("input.txt")
+	if err != nil {
+		fmt.Print(err)
+	}
+	input = string(fileBytes)
+	input = strings.TrimRight(input, "\n")
+	if len(input) == 0 {
+		panic("empty input.txt file")
+	}
+}
+
+func main() {
+	var part int
+	flag.IntVar(&part, "part", 1, "part 1 or 2")
+	flag.Parse()
+	fmt.Println("Running part", part)
+
+	if part == 1 {
+		ans := part1(input)
+		fmt.Println("Output:", ans)
+	} else {
+		ans := part2(input)
+		fmt.Println("Output:", ans)
+	}
+}
+
+func part1(input string) int {
+	var maxRed, maxGreen, maxBlue int
+	var possible bool
+	var sum, gameId int
+
+	// from puzzle description
+	maxRed = 12
+	maxGreen = 13
+	maxBlue = 14
+
+	for _, line := range strings.Split(input, "\n") {
+		parts := strings.Split(line, ":")
+		fmt.Sscanf(parts[0], "Game %d", &gameId)
+
+		hands := strings.Split(parts[1], ";")
+		possible = true
+		for _, hand := range hands {
+			cubes := strings.Split(hand, ",")
+			for _, cube := range cubes {
+				counts := strings.Fields(cube)
+				num, _ := strconv.Atoi(counts[0])
+				color := counts[1]
+				switch color {
+				case "red":
+					possible = possible && (num <= maxRed)
+				case "green":
+					possible = possible && (num <= maxGreen)
+				case "blue":
+					possible = possible && (num <= maxBlue)
+				}
+			}
+		}
+		if possible {
+			sum += gameId
+		}
+	}
+	return sum
+}
+
+func part2(input string) int {
+	var minRed, minGreen, minBlue int
+	var sum, gameId int
+	for _, line := range strings.Split(input, "\n") {
+		parts := strings.Split(line, ":")
+		fmt.Sscanf(parts[0], "Game %d", &gameId)
+
+		hands := strings.Split(parts[1], ";")
+
+		minRed = 0
+		minGreen = 0
+		minBlue = 0
+
+		for _, hand := range hands {
+			cubes := strings.Split(hand, ",")
+			for _, cube := range cubes {
+				counts := strings.Fields(cube)
+				num, _ := strconv.Atoi(counts[0])
+				color := counts[1]
+				switch color {
+				case "red":
+					if num > minRed {
+						minRed = num
+					}
+				case "green":
+					if num > minGreen {
+						minGreen = num
+					}
+				case "blue":
+					if num > minBlue {
+						minBlue = num
+					}
+				}
+			}
+		}
+		sum += minRed * minGreen * minBlue
+	}
+	return sum
+}

2023/day02/main_test.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"testing"
+)
+
+var example = `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`
+
+func Test_part1(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  int
+	}{
+		{
+			name:  "example",
+			input: example,
+			want:  8,
+		},
+		// {
+		// 	name:  "actual",
+		// 	input: input,
+		// 	want:  0,
+		// },
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := part1(tt.input); got != tt.want {
+				t.Errorf("part1() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_part2(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  int
+	}{
+		{
+			name:  "example",
+			input: example,
+			want:  2286,
+		},
+		// {
+		// 	name:  "actual",
+		// 	input: input,
+		// 	want:  0,
+		// },
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := part2(tt.input); got != tt.want {
+				t.Errorf("part2() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}