01.Java

01.java

		File file = new File("./input.txt");
		Scanner sc = new Scanner(file);

		Integer currentElf = 0;
		ArrayList<Integer> elfCalories = new ArrayList<>();
		elfCalories.add(0);

		while (sc.hasNextInt()) {

			String line = sc.nextLine();

			if (line.isBlank()) {
				// New Elf
				currentElf++;
				elfCalories.add(0);
			} else {
				Integer totalCalories = elfCalories.get(currentElf) + Integer.parseInt(line);
				elfCalories.set(currentElf, totalCalories);
			}

		}

		// Part 1
		System.out.println(elfCalories.stream().sorted().skip(elfCalories.size() - 1).findFirst().orElse(null));

		// Part 2
		System.out.println(elfCalories.stream().sorted().skip(elfCalories.size() - 3).reduce(0, (a, b) -> a + b));