test: add unit test for part two

internal/2015/DayFifteen/code.go

@@ -0,0 +1,109 @@
+package dayfifteen
+
+import (
+	"advent-of-code/internal/registry"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func init() {
+	registry.Register("2015D15", ParseInput, PartOne, PartTwo)
+}
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
+	return strings.Split(string(content), "\n")
+}
+
+type ingredient struct {
+	capacity   int
+	durability int
+	flavor     int
+	texture    int
+	calories   int
+}
+
+func parseIngredient(line string) ingredient {
+	parts := strings.Split(line, ": ")
+	props := strings.Split(parts[1], ", ")
+	var cap, dur, flav, tex, cal int
+
+	for _, prop := range props {
+		var name string
+		var value int
+		fmt.Sscanf(prop, "%s %d", &name, &value)
+		switch name {
+		case "capacity":
+			cap = value
+		case "durability":
+			dur = value
+		case "flavor":
+			flav = value
+		case "texture":
+			tex = value
+		case "calories":
+			cal = value
+		}
+	}
+
+	return ingredient{
+		capacity:   cap,
+		durability: dur,
+		flavor:     flav,
+		texture:    tex,
+		calories:   cal,
+	}
+}
+
+func calculateScore(ingredients []ingredient, amounts []int) int {
+	var capacity, durability, flavor, texture int
+	for idx, ing := range ingredients {
+		capacity += ing.capacity * amounts[idx]
+		durability += ing.durability * amounts[idx]
+		flavor += ing.flavor * amounts[idx]
+		texture += ing.texture * amounts[idx]
+	}
+	if capacity < 0 {
+		capacity = 0
+	}
+	if durability < 0 {
+		durability = 0
+	}
+	if flavor < 0 {
+		flavor = 0
+	}
+	if texture < 0 {
+		texture = 0
+	}
+	return capacity * durability * flavor * texture
+}
+
+func findMaxScore(ingredients []ingredient, remaining int, amounts []int, index int) int {
+	if index == len(ingredients)-1 {
+		amounts[index] = remaining
+		return calculateScore(ingredients, amounts)
+	}
+	maxScore := 0
+	for i := 0; i <= remaining; i++ {
+		amounts[index] = i
+		score := findMaxScore(ingredients, remaining-i, amounts, index+1)
+		if score > maxScore {
+			maxScore = score
+		}
+	}
+	return maxScore
+}
+
+func PartOne(data []string) int {
+	var ingredients []ingredient
+	for _, line := range data {
+		ingredients = append(ingredients, parseIngredient(line))
+	}
+	amounts := make([]int, len(ingredients))
+	return findMaxScore(ingredients, 100, amounts, 0)
+}
+
+func PartTwo(data []string) int {
+	return 0
+}

internal/2015/DayFifteen/code_test.go

@@ -14,3 +14,11 @@ func TestPartOne(t *testing.T) {
 		t.Errorf("PartOne() = %d, want %d", got, expected)
 	}
 }
+
+func TestPartTwo(t *testing.T) {
+	expected := 57600000
+	got := PartTwo(testInput)
+	if got != expected {
+		t.Errorf("PartTwo() = %d, want %d", got, expected)
+	}
+}