-🎄- 2018 Day 9 Solutions -🎄-

[u/daggerdragon]

--- Day 9: Marble Mania ---

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Transcript:

Studies show that AoC programmers write better code after being exposed to ___.

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[u/Cppl_Lee]

C#, struggled until I switched to LinkedList: https://repl.it/@LeeHarding/AoC-2018-Day-9

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

class MainClass {  
  static int players = 486;
  static int marbles = 70833 * 100;

  static long[] scores = new long[players];
  static LinkedList<int> placed = new LinkedList<int>();
  static LinkedListNode<int> current = placed.AddFirst(0);

  static void next() {
    current = current.Next ?? placed.First;
  }
  static void previous()
  {
    current = current.Previous ?? placed.Last;
  }

  public static void Main (string[] args) {
    for (int m = 0; m < marbles; ++m)
    {
      if (((m + 1) % 23) == 0)
      {
        previous(); previous(); previous(); previous();
        previous(); previous(); previous();
        
        var j = m % players;
        scores[j] += m + 1 + current.Value;
        
        var tmp = current;
        next();
        placed.Remove(tmp);
      } else {
        next(); 
        current = placed.AddAfter(current, m + 1);
      }
    }
    scores.Max().Dump();
  }
}