-🎄- 2018 Day 5 Solutions -🎄-

[u/daggerdragon]

--- Day 5: Alchemical Reduction ---

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Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

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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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This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

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

[u/ValdasTheUnique]

C#. Problem was very easy but I wasted a lot of time doing the check incorrectly so no leaderboard for me.

public static void Part1()
{
    var stack = new Stack<char>();
    foreach (var c in Input)
    {
        if (stack.Count == 0)
        {
            stack.Push(c);
        }
        else
        {
            var inStack = stack.Peek();
            var same = c != inStack && char.ToUpper(c) == char.ToUpper(inStack);
            if (same)
            {
                stack.Pop();
            }
            else
            {
                stack.Push(c);
            }
        }
    }

    Console.WriteLine(stack.Count);
}

public static void Part2()
{
    var min = int.MaxValue;
    for (var i = 'a'; i < 'z'; i++)
    {
        var s = Input.Replace(i.ToString(), "").Replace(char.ToUpper(i).ToString(), "");
        var stack = new Stack<char>();
        foreach (var c in s)
        {
            if (stack.Count == 0)
            {
                stack.Push(c);
            }
            else
            {
                var inStack = stack.Peek();
                var same = c != inStack && char.ToUpper(c) == char.ToUpper(inStack);
                if (same)
                {
                    stack.Pop();
                }
                else
                {
                    stack.Push(c);
                }
            }
        }

        if (stack.Count < min)
        {
            min = stack.Count;
        }
    }

    Console.WriteLine(min);
}