Advent of Code 2018

Advent of Code.md

Advent of Code

https://adventofcode.com/2018/

day01.js

// Answer to Question 1:
const changes = [-10,-12,+1,+14,+11,-19,-4,+10,+10,-12,-13,-10,-8,+11,+3,-10,+8,+5,-14,+7,+12,+12,+14,-1,+17,-5,+9,-15,+8,-16,+9,+6,+17,-11,+19,+11,-9,-1,-8,-16,-5,+6,+2,+6,+12,+15,+16,-6,-8,-5,+11,-9,+19,+19,-5,-12,-17,-20,+9,-6,-2,+20,+15,-8,+15,+19,-5,-17,-9,+1,-9,-11,-19,-1,-15,+18,-4,+19,+3,+21,+5,-1,+8,+9,+9,-16,+17,-15,+18,+14,+8,-13,-2,-15,+13,+19,-13,+5,+16,+16,+7,+8,-19,+3,-12,+18,-16,-19,+8,-16,+20,+15,-5,-17,+15,+14,-2,+18,-6,+5,+16,+13,-8,-9,-1,+13,+18,-2,+16,-4,+19,+6,+14,-6,-16,-10,-5,-15,+11,+10,+18,+8,-2,+15,-9,+7,+10,+9,-6,+1,-17,-12,+19,+14,-9,-18,+20,+12,+10,+14,+6,+9,-18,+4,+15,+15,+3,+9,-4,-19,+8,+16,+19,-12,-1,+16,+11,+13,-8,+4,+18,+10,-11,+18,-8,+19,-4,-5,-12,-3,-10,-11,-18,-7,+3,+14,+18,+2,-7,-12,+14,+12,+13,-1,+13,-1,+15,+13,-1,-17,-4,+17,-3,+13,+5,-19,+17,+10,+6,-15,+11,+16,+11,+20,+19,+5,-11,-2,-12,-6,-11,-14,+5,+10,-23,+14,-11,+22,-1,-14,-35,-23,+11,+4,+10,-6,+19,-5,+4,-13,-7,+11,-24,-17,+9,-17,+11,+2,-4,-10,-24,+14,+15,+19,+7,-2,+11,-13,-8,-8,-14,-17,+6,+8,-16,-18,+1,-21,-14,+8,-2,+20,-19,+9,-15,-6,-7,+4,-3,-8,+16,+15,-26,+18,-22,-16,-3,-17,-18,+4,+5,+3,-1,+3,+2,+3,+7,-5,+20,-11,+15,-6,-19,-24,-6,-20,+13,-4,-18,+15,+9,+16,+12,-5,+16,+9,-4,-14,-9,-19,-5,-16,-16,+5,-4,+12,-15,-15,-14,+4,-18,-12,-4,+6,+9,-12,+14,+9,-6,+3,+8,+4,+7,-14,-15,-18,+12,-19,-14,-15,-16,+15,-8,+14,-4,-21,+7,-12,-2,-10,-6,+14,+14,-9,-14,-16,+2,+7,+5,-15,-15,+19,-16,-5,-16,-19,+9,-27,-8,+6,+1,-14,-9,-50,-9,-21,+5,-20,-19,+6,-11,+6,+1,-17,-14,-2,+8,-4,+16,+1,-3,-9,+20,+15,-22,-3,-13,-12,-25,+5,-13,-2,-8,-11,+17,+3,-7,+13,+1,+18,-13,+1,+7,-15,-43,-6,-10,-9,-20,-7,-8,-15,-9,+13,-9,+24,+13,+5,-8,-15,-4,-4,-4,-14,-21,+16,+15,-14,-20,-20,-15,-19,-41,+16,+3,+8,-22,-30,+8,+40,+15,+24,-7,+22,+10,+15,+9,+28,+14,+2,+14,+6,+17,+1,+30,+5,-2,+46,+24,+46,-3,-7,+35,+16,+13,-21,+28,+13,-25,+180,+25,+5,-9,+23,-5,-2,+13,-12,+2,-25,-5,+18,-24,+45,+17,-7,+22,-152,-11,+4,+50,+129,-7,+22,+109,-56,+80,+29,-75060,-2,-14,+7,-17,-5,+6,-3,+18,+19,-14,-12,-6,+9,-5,-13,-6,-3,-15,+13,+3,-18,-11,+16,-2,+10,-14,-7,+19,-20,+15,+10,+12,+10,+16,-11,+14,-5,+14,+11,-5,+1,-13,+1,+18,-10,+25,+13,-17,+15,-18,+1,-6,-12,+5,-7,+18,-6,-18,-17,-5,-15,-1,-15,+1,-12,+9,+16,+8,+5,+1,+9,+18,-13,-30,-27,-19,+2,-16,-19,-10,-18,+21,+18,-5,+14,+9,-6,+2,-16,-11,+1,+18,-4,+19,+7,+6,-8,+25,-50,+6,-21,+6,-2,+14,-11,+10,-9,+16,+25,-61,-17,-14,+13,+3,-14,-4,-1,+9,-1,-4,-5,+7,-15,+7,+16,+6,-2,-11,-11,-13,+11,-12,-13,-8,+3,-13,+16,-1,-14,+19,+4,+10,+12,+26,+6,+4,+24,-31,+9,-10,-23,-13,+3,-18,-9,-6,+1,-2,+15,-10,-17,-17,+15,+9,+4,+19,-4,+12,+11,-25,+16,+4,-2,+39,+49,+9,+96,+4,+19,+3,+11,+25,+14,+11,-5,-26,-8,-16,+11,+2,+2,-1,-10,-45,-160,-31,-3,-43,-18,+19,+3,+4,+11,-16,-19,-22,+6,+2,+10,-11,-17,+7,+1,+15,+17,-19,+6,-26,-7,-9,+19,+2,+6,-22,+2,-8,+5,+7,+9,+8,-16,+2,-19,-19,-3,+16,+5,+4,-18,-11,-19,+16,-15,+7,-1,-9,-19,+11,-17,-5,+7,-11,+16,-19,+5,+21,-2,+12,+14,-7,+18,-8,+10,-11,-17,+3,-13,+19,-3,+10,+17,+17,-18,+7,-2,-2,+12,-6,+19,-20,-15,-11,-27,+8,+18,+9,-1,-2,+19,+7,+12,+32,+14,+13,-9,-14,+20,+18,-4,-49,-6,-10,-7,-4,-9,-6,-37,-21,-2,+5,+12,+4,-33,-4,-13,-4,+13,-19,-7,-16,-1,-1,+8,-14,-15,+11,-10,-14,-22,-11,+10,-3,+7,+9,-15,+16,-7,-1,+2,+20,+11,-1,+6,-2,+3,+3,+2,-20,-10,+11,-10,+13,-1,+20,+7,+7,+5,+1,+4,-13,+15,-3,+2,-4,-3,-1,+13,-15,-14,-2,-6,+3,+13,-19,-11,+8,-21,-2,-23,-18,+20,+7,+6,-28,+7,-33,+13,-16,-18,-10,-18,+13,+8,-14,-13,-2,+4,-14,-7,-18,-20,-4,-5,+8,-4,+16,+21,+20,-8,-14,-2,-14,-22,+14,+36,+32,-28,+1,-21,+8,+14,+75784]

const sum = (a, b) => a + b

changes.reduce(sum)

// Answer to Question 2:

let frequencies = [];
let frequency = 0;
let index = 0;
let firstFreq;

while (!firstFreq) {
  change = changes[index % changes.length]
  frequency += change

  if (frequencies.includes(frequency)) {
    firstFreq = frequency
  } else {
    frequencies.push(frequency)
    index++
  }
}

day02.rb

# Answer to Question 1:
identifiers = ["fzostwblnqkhpuzxirnevmaycq","fzastwblgqkupujxirnevmaucd","fzostwbxgakhpujxirnevmayci","uzosmwblgqkhlujxirnevmaycd","bzostwblgqkhpujxirnenfaycd","fzostwblghkhpujxibneemaycd","fzostwblgrkkpujxirnevqaycd","fzostwblgqkhpkjxirqkvmaycd","fzostwblgqdxpujbirnevmaycd","fzostwblgykhfujxirfevmaycd","fzostwbvgskhpujxirnevmagcd","flostwblgokhpuixirnevmaycd","fzostwblgzkhppjxirnevxaycd","ftosuwblgqkhpujxirnevmeycd","fzostkblgqkzpujxirnrvmaycd","fuostwbugqkhnujxirnevmaycd","frostwblgqkhpujsirneamaycd","bzostwblgqkhpajxirnevmuycd","fzysttbluqkhpujxirnevmaycd","czostgblgqkhpujxirnevmgycd","fzostwbcgqkhpujxirnevmavcr","vzostwbdgqrhpujxirnevmaycd","fzostwblgxkhpujxirnekmdycd","fzostwblgdkspzjxirnevmaycd","fzoqtwblgquhpujxirnevkaycd","fzostwblgqjhfujxirnevmayzd","fyostwblgtkhpujxilnevmaycd","izostwblzqkhpupxirnevmaycd","fzoaurblgqkhpujxirnevmaycd","fzostjblgqkhpbjxirbevmaycd","fzostwblgqkhpujmirngvmayca","fxostwbhgqkhiujxirnevmaycd","fzostwblngkhpujxirnemmaycd","fzosgwblgqkhpujxirnlvqaycd","bpostwblgqkhxujxirnevmaycd","fzhstwblgqshpujxirnepmaycd","fzootwbegqkhwujxirnevmaycd","fzmstwblgqkhmujxirnevsaycd","fzostwolgqkhpujxirnevmaysp","foostwblgqohpujxirnevmayyd","fzostwblgqkhgujxgrnevqaycd","fzostwbltqkhjujxipnevmaycd","fsostwblgqkhfujxirnevmayck","fzostwmlgqkbpujxifnevmaycd","fdostwblgqkhsujxirnecmaycd","fzostwblgquhpejxiinevmaycd","fzoqtwblgqkhkujxirnevmaywd","fzostwblmqkmpujxirnyvmaycd","fzjstwblgqkhpuyxirneomaycd","fzortwblgqkhpzjxprnevmaycd","fzosnwulgqkhpujxirnevpaycd","fzostwbegqkvpujxirnevmaykd","fzostwylzqkypujxirnevmaycd","fioshwblgqehpujxirnevmaycd","fzostwbliqkhoujxirnesmaycd","fzostwblgqkhpujdirnelmqycd","fzmstwblgqkhpujxirnnvpaycd","fzostwbtgqkhcujxirnevmaycz","fzostwblgqkfpujeignevmaycd","fzostwbegqkhpuvxirndvmaycd","fzostwblgqkcpujxmrnevmaycp","fvostwblgqkhpyjxirnevmaycx","fzostwblgqkhpufxirnevmzacd","fzisjwblglkhpujxirnevmaycd","fzosowbliqkhgujxirnevmaycd","fzostwblgqkhpujxirnyvmaywl","fzostwbllqnzpujxirnevmaycd","fzostwblgquhpujxirneomayci","fzostwblgqjepujximnevmaycd","fzostwblgqrhbujxijnevmaycd","fzostoblgqkhpujxirnevmoynd","fzortwblgqkhpujxixnevjaycd","fzostwhlgqkapujxirnevmaych","fzostwblgakhpujxirnevfayct","faostwblgqohpljxirnevmaycd","fzostwbhgqkhpujxirnyvcaycd","fjostwblgqkhpwjxirnevjaycd","fzostwblgqklpuixirnevmayxd","fzostwblgqkhhujxirncvmayce","fzostwblzqkhpzjxkrnevmaycd","fzostwblqqkbpujxirnevmcycd","ffostwblxqkhpujxirnevmayxd","fzostwblgqkhpbuxirnefmaycd","szostiblgqkhpujxirnevoaycd","fhlstwblgqkhpujxirnevmaycb","fzostwblgwfhpujxirnevmayed","fyostwblgqkhzujxirnevmayjd","fzostwblgqkvrujxirnevmaucd","fzestwblghkhpujxirnevmaycq","foostwbkgqkhhujxirnevmaycd","fpxstwblgqkhpujxirzevmaycd","fsostwtlgqmhpujxirnevmaycd","feostwelgqkhpumxirnevmaycd","fzostwbvgqkhpujkirnevmayce","fzmsewblgqahpujxirnevmaycd","fzsstsblgkkhpujxirnevmaycd","fzostwblgqkhxajxirneumaycd","fzostwblmqkhpujyisnevmaycd","gzostwblgqkhphjxirnevmavcd","fzostwblgckgpujxirnzvmaycd","qzostdblgqkhpujxirnevmaywd","fzoshwblgskhpufxirnevmaycd","fzosdwblgqkhpujkirnevjaycd","fzvstwblgqkhpuixdrnevmaycd","szostwblgqxhpujeirnevmaycd","fzosvwblgtkhpujxirnevmoycd","fzoscwblgqkkpujxirnevmvycd","fzostsblgqnlpujxirnevmaycd","fzostwblgmkhpujxlrnevjaycd","fzosnwblgqklpugxirnevmaycd","fcostwblgqpmpujxirnevmaycd","ozostwblgbkhpujxirnevmafcd","fzostwbagqkhiujxirneemaycd","fzosxwblgqkhpumxirneymaycd","fpostkblgqkhpujxianevmaycd","fzostwblgvkhhujxirnevmaycl","fzobtwtlgqkhpuwxirnevmaycd","fzostwvwgqkhpujxirtevmaycd","xzostwglgqkhpujtirnevmaycd","fzostwblgvkhtujxirnzvmaycd","jzostwblgqkhpujxirrevmvycd","pzostwbagqkhpujxirnevjaycd","fzostwclgqkhpujxirnhvmeycd","fzostwblglkhpujxirnevmayrf","fzoskwblnqkhpujxirnevmaysd","fzostbblgqkhpujxirnevmjycw","fzostwblggobpujxirnevmaycd","fzostwblgckhpijxirnevmayxd","fiostwrlgqkhpujxirnevmayck","frfstwblvqkhpujxirnevmaycd","fzowvwblgqkhpujsirnevmaycd","fzostwblgquhgujxirnevmiycd","fzoztwblgqkhpujxvrnevmaycj","fzostnbtgqkhpujxixnevmaycd","fzfstwblgjkrpujxirnevmaycd","fzostwblpqkhpdrxirnevmaycd","fivstwblgqkhpuixdrnevmaycd","fzostwbpgqkhpdjxirnewmaycd","fzostwblgqkhpdjxsrngvmaycd","fzostwblsqkhpujxisnxvmaycd","fcosvwblgqkhpujxirnevmavcd","fzostwrlgekhgujxirnevmaycd","fzostwblgqkhpujxindeimaycd","uzostwblgqshpujxirnevmwycd","fzostwzliqkhpujxirnevmaycu","zzostwbtgqkhpijxirnevmaycd","fzoltwblgqkhpujxinncvmaycd","fzostwblgqkzpujxprnevmayhd","fqostwblgqkhpujrirnevmzycd","jzostwblgqkhpuzxkrnevmaycd","fzostwblgqkhpuwxirszvmaycd","fzostwblgqkhpxjxilnevdaycd","fpmstwblgqkhpujxirnwvmaycd","fzoejwblqqkhpujxirnevmaycd","fzostwblgkshzujxirnevmaycd","fzoatqblgqxhpujxirnevmaycd","fzostwblgpkhpujiipnevmaycd","fzostwblgqghpujgbrnevmaycd","izosowblgqkhpujxirnejmaycd","fzostwblgqthpujxjrnevmalcd","fzovtwbcgqkhpujxicnevmaycd","fzoatwblgqkhpujxidntvmaycd","kzpstwblgqihpujxirnevmaycd","fzosawnlgqkhpujxibnevmaycd","fzostwblgqkhpujxarnevdajcd","bzostwblgqkhpujxvrnevmrycd","fzostwblgqkhpwfxirnevmazcd","fzostwblgqknpujyiqnevmaycd","zzostwblgqkhpujyirneqmaycd","flosiwblgqihpujxirnevmaycd","fzoetwblgqkhxujxirnevmeycd","fznstwbugqkhpujxibnevmaycd","fzbstwblgq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identifiers = identifiers.map(&:chars).sort

id_counts = identifiers.map {|id| Hash[id.uniq.zip(id.uniq.map {|char| id.count char })]}

twos_and_threes = id_counts.reduce(twos: 0, threes: 0) do |memo, id|
  memo[:twos] += 1 if id.values.include?(2)
  memo[:threes] += 1 if id.values.include?(3)
  memo
end

puts twos_and_threes.values.reduce(&:*)

# Answer to Question 2

def diff_count first, second
  first.each_index.reduce(0) do |diff_count, i|
    first[i] == second[i] ? diff_count : diff_count + 1
  end
end

catch :outer do
  identifiers.each_index do |outer_index|
    catch :inner do
      identifiers.each_index do |inner_index|
        throw(:inner) if identifiers[outer_index + inner_index + 1].nil?
        puts "outer: #{outer_index}\t inner: #{inner_index}"
        first, second = identifiers[outer_index], identifiers[outer_index + inner_index + 1]

        if diff_count(first, second) == 1
          puts "1st: #{first.join}\n2nd: #{second.join}"
          throw :outer
        end
      end
    end
  end
end

# Alternately:

require 'continuation'

callcc do |outer|
  identifiers.each_index do |outer_index|
    callcc do |inner|
      identifiers.each_index do |inner_index|
        inner.call if identifiers[outer_index + inner_index + 1].nil?
        puts "outer: #{outer_index}\t inner: #{inner_index}"
        first, second = identifiers[outer_index], identifiers[outer_index + inner_index + 1]

        if diff_count(first, second) == 1
          puts "1st: #{first.join}\n2nd: #{second.join}"
          outer.call
        end
      end
    end
  end
end