Solved Day 15 (2015) - Science for Hungry People

Author: SimonBaars

src/main/java/com/sbaars/adventofcode/year15/days/Day15.java

@@ -1,23 +1,120 @@
 package com.sbaars.adventofcode.year15.days;
 
 import com.sbaars.adventofcode.year15.Day2015;
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 public class Day15 extends Day2015 {
- public Day15() {
- super(15);
- }
-
- public static void main(String[] args) {
- new Day15().printParts();
- }
-
- @Override
- public Object part1() {
- return "";
- }
-
- @Override
- public Object part2() {
- return "";
- }
+
+ private static final int TOTAL_TEASPOONS = 100;
+ private final List<Ingredient> ingredients = new ArrayList<>();
+
+ public Day15() {
+ super(15);
+ parseInput();
+ }
+
+ public static void main(String[] args) {
+ Day15 day = new Day15();
+ day.printParts();
+ new com.sbaars.adventofcode.network.Submit().submit(day.part1(), 2015, 15, 1);
+ }
+
+ private void parseInput() {
+ Pattern pattern = Pattern.compile("(\\w+): capacity (-?\\d+), durability (-?\\d+), flavor (-?\\d+), texture (-?\\d+), calories (-?\\d+)");
+ Arrays.stream(day().split("\n"))
+ .map(pattern::matcher)
+ .filter(Matcher::find)
+ .map(matcher -> new Ingredient(
+ matcher.group(1),
+ Integer.parseInt(matcher.group(2)),
+ Integer.parseInt(matcher.group(3)),
+ Integer.parseInt(matcher.group(4)),
+ Integer.parseInt(matcher.group(5)),
+ Integer.parseInt(matcher.group(6))
+ ))
+ .forEach(ingredients::add);
+ }
+
+ @Override
+ public Object part1() {
+ return findBestScore();
+ }
+
+ @Override
+ public Object part2() {
+ return 0; // Implement in next part
+ }
+
+ private long findBestScore() {
+ return generateCombinations(TOTAL_TEASPOONS, ingredients.size())
+ .stream()
+ .mapToLong(this::calculateScore)
+ .max()
+ .orElse(0);
+ }
+
+ private List<List<Integer>> generateCombinations(int total, int parts) {
+ List<List<Integer>> result = new ArrayList<>();
+ generateCombinationsHelper(total, parts, new ArrayList<>(), result);
+ return result;
+ }
+
+ private void generateCombinationsHelper(int remaining, int parts, List<Integer> current, List<List<Integer>> result) {
+ if (parts == 1) {
+ List<Integer> combination = new ArrayList<>(current);
+ combination.add(remaining);
+ result.add(combination);
+ return;
+ }
+
+ for (int i = 0; i <= remaining; i++) {
+ List<Integer> newCurrent = new ArrayList<>(current);
+ newCurrent.add(i);
+ generateCombinationsHelper(remaining - i, parts - 1, newCurrent, result);
+ }
+ }
+
+ private long calculateScore(List<Integer> amounts) {
+ int capacity = 0;
+ int durability = 0;
+ int flavor = 0;
+ int texture = 0;
+
+ for (int i = 0; i < ingredients.size(); i++) {
+ Ingredient ingredient = ingredients.get(i);
+ int amount = amounts.get(i);
+
+ capacity += ingredient.capacity * amount;
+ durability += ingredient.durability * amount;
+ flavor += ingredient.flavor * amount;
+ texture += ingredient.texture * amount;
+ }
+
+ if (capacity <= 0 || durability <= 0 || flavor <= 0 || texture <= 0) {
+ return 0;
+ }
+
+ return (long) capacity * durability * flavor * texture;
+ }
+
+ private static class Ingredient {
+ private final String name;
+ private final int capacity;
+ private final int durability;
+ private final int flavor;
+ private final int texture;
+ private final int calories;
+
+ public Ingredient(String name, int capacity, int durability, int flavor, int texture, int calories) {
+ this.name = name;
+ this.capacity = capacity;
+ this.durability = durability;
+ this.flavor = flavor;
+ this.texture = texture;
+ this.calories = calories;
+ }
+ }
 }