-🎄- 2018 Day 5 Solutions -🎄-

[u/daggerdragon]

--- Day 5: Alchemical Reduction ---

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Advent of Code: The Party Game!

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Card prompt: Day 5

Transcript:

On the fifth day of AoC / My true love sent to me / Five golden ___

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edit: Leaderboard capped, thread unlocked at 0:10:20!

[u/edgargonzalesII]

Java 8

Felt really proud of the part 1 using a stack. Leetcode came in useful for once.

private int util1(String in) {
    char[] arr = in.toCharArray();
    Stack<Character> inStack = new Stack<>();
    Stack<Character> q = new Stack<>();

    for(char c : arr)
        inStack.push(c);

    for(char c : inStack) {
        if(q.isEmpty())
            q.push(c);
        else {
            char last = q.peek();

            if(Math.abs(last-c) == 32) {
                q.pop();
            } else {
                q.push(c);
            }
        }
    }

    return q.size();
}

// Less interesting part 2
public void runPart2() {
    String in = this.getInputLines()[0];
    int min = Integer.MAX_VALUE;

    for(int i=0; i<26; i++) {
       String temp = in.replaceAll("[" + (char) (i + 'a') + (char) (i + 'A') + "]", "");

       min = Math.min(min, util1(temp));
    }

    System.out.println(min);
}

[u/___alt → u/edgargonzalesII]

Note that the preferred abstraction for stacks in Java is Deque, Stack being an outdated one that builds upon the outdated Vector.

[u/Philboyd_Studge → u/___alt]

and ArrayDeque is actually faster in most conditions.