Main.java

static class Quantity {
        public int amount;
        public String name;
        public int id;

        public Quantity(int amount, String name, int id) {
            this.amount = amount;
            this.name = name;
            this.id = id;
        }

        @Override
        public String toString() {
            return amount + " " + name;
        }
    }

    static class Recipe {
        public ArrayList<Quantity> ingredients = new ArrayList<>();
        public Quantity output;

        public Recipe(Quantity output) {
            this.output = output;
        }

        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder();
            sb.append(ingredients.stream().map(x -> x.toString()).collect(Collectors.joining(", ")));
            sb.append(" => ");
            sb.append(output.toString());
            return sb.toString();
        }
    }

    private static void day14Part1() {
        try {
            BufferedReader br = getBufferedReader("14.txt");
            String line;
            int x = 0;
            HashMap<String, Integer> map = new HashMap<>();
            HashMap<Integer, Recipe> recipeMap = new HashMap<>();
            while((line = br.readLine()) != null) {
                line = line.replaceAll(",", "");
                String[] split = line.split(" ");
                ArrayList<Quantity> ingredients = new ArrayList<>();
                for(int i = 0; i < split.length-3;i+=2) {
                    int amount = Integer.parseInt(split[i]);
                    if (!map.containsKey(split[i + 1])) {
                        map.put(split[i+1], x);
                        x++;
                    }
                    int ingredient = map.get(split[i+1]);
                    ingredients.add(new Quantity(amount, split[i+1], ingredient));

                }
                String outputName = split[split.length-1];
                if(!map.containsKey(outputName)) {
                    map.put(outputName, x);
                    x++;
                }
                int outputAmount = Integer.parseInt(split[split.length-2]);
                Recipe r = new Recipe(new Quantity(outputAmount, outputName, map.get(outputName)));
                r.ingredients = ingredients;
                recipeMap.put(r.output.id, r);
            }
            long[] excess = new long[x];
            long[] currentlyWant = new long[x];
            int m = 0;
            long count = 1;
            while(currentlyWant[0] <= 1_000_000_000_000L) {
                currentlyWant[map.get("FUEL")] = count;
                m += count;
                //System.out.println(m);
                while(!allOre(currentlyWant)) {
                    int i = 1;
                    while(currentlyWant[i] <= 0) {
                        i++;
                    }
                    Recipe iReducer = recipeMap.get(i);
                    ArrayList<Quantity> prerequisites = iReducer.ingredients;
                    long outputToProduce = currentlyWant[i] - excess[i];
                    long productionMultiplier = outputToProduce / iReducer.output.amount +
                            (outputToProduce % iReducer.output.amount == 0 ? 0 : 1);
                    for (Quantity q : prerequisites) {
                        long ingredientNeeded = q.amount * productionMultiplier;
                        currentlyWant[q.id] += ingredientNeeded;
                    }
                    currentlyWant[i] = 0;
                    excess[i] = productionMultiplier * iReducer.output.amount - outputToProduce;
                    for(int j = 0; j < excess.length; j++) {
                        long leftOver = excess[j] - currentlyWant[j];
                        if(leftOver >= 0) {
                            excess[j] = leftOver;
                            currentlyWant[j] = 0;
                        } else {
                            currentlyWant[j] = leftOver * -1;
                            excess[j] = 0;
                        }
                    }
                }
            }
            System.out.println(m);
            System.out.println(currentlyWant[0]);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static boolean allOre(long[] want) {
        for(int i = 1; i < want.length; i++) {
            if(want[i] > 0) {
                return false;
            }
        }
        return true;
    }