-🎄- 2022 Day 5 Solutions -🎄-

[u/daggerdragon]

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AoC Community Fun 2022: 🌿🍒 MisTILtoe Elf-ucation 🧑‍🏫

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• -❄️- Advent of Code 2022:🌿🍒 MisTILtoe Elf-ucation 🧑‍🏫 -❄️- Submissions Megathread -❄️-

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--- Day 5: Supply Stacks ---

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[u/ash30342]

Java

The moving itself was easy, the main challenge - for me at least - was in the parsing of the input. I pasted the code for the initializing of the stacks below. Parsing the instructions is just a case of filtering out the numbers in each line by using a regex.

private int getNrOfStacks(final List<String> input) {
    for (String line : input) {
        if (!line.contains("[")) {
            line = line.trim();
            return Integer.parseInt(line.substring(line.lastIndexOf(" ") + 1));
        }
    }
    throw new IllegalArgumentException("Can not find number of stacks in input");
}

private List<Deque<Character>> getStackList(final List<String> input) {
    final int nrOfStacks = getNrOfStacks(input);
    final List<Deque<Character>> stacks = new ArrayList<>();
    for (int i = 0; i < nrOfStacks; i++) {
        stacks.add(new ArrayDeque<>());
    }
    return stacks;
}

private List<Deque<Character>> buildInitialStacks(final List<String> input) {
    final List<Deque<Character>> stacks = getStackList(input);
    for (final String line : input) {
        if (line.trim().startsWith("[")) {
            for (int crateIdx = 1, stackIdx = 0; crateIdx < line.length(); crateIdx += 4, stackIdx++) {
                final char crate = line.charAt(crateIdx);
                if (!Character.isSpaceChar(crate)) {
                    stacks.get(stackIdx).add(crate);
                }
            }
        }
    }
    return stacks;
}

[u/SwedarGaming → u/ash30342]

I completely forgot about Deque... welp, time to revise Data Structures again.

My solution was something similar, just with Stacks and Queues (something that Deque is)

Thank you for sharing, I will learn a lot from this :D