— Day 1: Historian Hysteria —

Mix.install([{:kino_aoc, "~> 0.1"}])

Part 1

{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2024", "1", System.fetch_env!("LB_AOC_SESSION_COOKIE"))

{:ok,
 "85215   94333\n24582   34558\n98037   94333\n75786   66247\n45656   85863\n70998   87003\n30367   62007\n81780   23161\n90260   65786\n24710   86514\n14018   34310\n43565   47888\n59781   79173\n47761   71538\n85892   22181\n25701   61839\n18264   33438\n33747   43258\n39697   94333\n61838   37358\n70437   22496\n23562   26799\n11216   34419\n63191   11393\n88615   31544\n93481   62720\n29534   40919\n29935   18758\n95190   87857\n51306   33515\n30938   29652\n77253   30646\n66807   67041\n75203   67041\n15696   61800\n73541   29496\n52063   51002\n55826   40919\n79183   35633\n77348   44025\n65423   33750\n65816   10624\n52110   89611\n18201   22051\n27748   66807\n92259   42784\n14988   33500\n58623   64359\n88260   90432\n62079   77685\n45698   40919\n91705   64359\n53661   73356\n93541   28465\n76689   96938\n60498   93056\n25784   65786\n32811   24732\n62264   72520\n41995   43258\n38545   84426\n19555   72520\n73703   78074\n86068   72520\n25850   87009\n49433   10684\n74291   61839\n40711   10516\n37728   82526\n80842   40919\n24677   23062\n29575   52605\n20692   77673\n82910   68845\n33830   62419\n68434   73604\n62401   84426\n82646   70854\n38398   56339\n79408   51171\n63734   27770\n13556   24577\n75123   37015\n61363   69734\n95609   86251\n88545   27770\n50893   74026\n14882   87009\n91379   33438\n60224   52605\n72679   47888\n75505   59781\n10186   62720\n88379   64359\n90496   67041\n73586   93056\n95670   63191\n87141   59781\n13919   74934\n98555   74846\n87897   32687\n21880   62687\n29658   50213\n96248   83521\n15492   86906\n29496   53112\n25334   27594\n20643   86251\n56611   39477\n29416   24577\n74832   63164\n43193   43258\n81875   75725\n61800   61927\n24065   94333\n83853   31467\n17180   10130\n43720   37354\n65647   45425\n51476   10461\n57574   93056\n31072   83739\n75113   19490\n79797   26799\n72214   11294\n13116   48228\n93787   33438\n46134   19254\n40985   28931\n25988   11393\n23062   59151\n79383   11393\n75339   89198\n79708   29496\n13058   61839\n16278   45698\n80414   14142\n16351   40919\n54813   43258\n81250   87434\n50921   61839\n53645   43258\n70432   22523\n81070   32306\n38985   31359\n19798   99501\n92509   43258\n25063   66000\n44665   33438\n64806   93056\n74946   26300\n48029   30646\n77560   83292\n82468   95064\n29223   71914\n87584   63191\n93056   26799\n55648   29949\n14352   48844\n49873   34111\n56227   45698\n67703   63191\n68135   30646\n44722   90812\n65476   78955\n82704   47888\n50424   23079\n51796   70111\n85079   22013\n61910   66098\n84132   89544\n47927   62720\n61766   78856\n38484   42757\n57255   93056\n48855   78836\n73127   78836\n21236   61839\n15138   94333\n26829   65786\n48823   93140\n28401   63191\n75082   42757\n41215   26799\n67176   19254\n13673   78836\n53842   26386\n41964   59781\n46737   21097\n52719   29652\n20212   76559\n89201   82291\n98568   63191\n55425   93322\n69878   63283\n36501   27429\n16724   47888\n61592   81085\n41114   93056\n44198   47888\n47061   86251\n45289   56992\n47597   15576\n18834   66807\n31018   40919\n40775   78266\n25185   76021\n48462   64359\n26799   32811\n37199   19555\n94411   77560\n45846   48696\n16862   77508\n77988   94333\n89121   66807\n41240   94333\n88088   59151\n52125   29652\n12932   13054\n61211   28578\n26024   87009\n26312   55718\n14585   45698\n65939   91730\n68138   59781\n70317   78836\n83217   78836\n22036   26799\n63215   66807\n54110   21264\n12981   33069\n61857   29652\n54637   94333\n15241   93056\n19897   33438\n77229   86251\n55685   37316\n30161   66807\n61780   14101\n19289   17661\n48121   51324\n99355   72435\n62767   32811\n98670   19490\n85332   31012\n92588   18461\n67574   94379\n90643   66607\n95487   66807\n33530   46429\n87009   23062\n61978   27770\n53891   19254\n64426   58297\n70651   61800\n40653   40474\n45888   33438\n55241   44527\n11126   42398\n92609   93056\n21760   22129\n72079   51542\n41177   26196\n67610   68036\n62720   45698\n38295   64359\n69482   93056\n24219   66807\n69511   45698\n30242   24577\n46626   18573\n36316   80909\n40214   72520\n16785   10921\n27770   11393\n70571   43258\n50406   30875\n76411   98707\n75186   77560\n80536   11587\n74209   78836\n20188   72520\n30587   57435\n44135   58144\n29251   46185\n73362   45698\n52443   53860\n61094   46357\n12167   47231\n51846   62720\n75168   23761\n97509   65786\n29546   " <> ...}

defmodule HistorianHysteria do
  # 1 | 2
  def lists(input) do
    input
    |> String.split("\n")
    |> Enum.reduce([[], []], fn ids, [list_l, list_r] ->
      [l, r] = String.split(ids)

      [[String.to_integer(l) | list_l], [String.to_integer(r) | list_r]]
    end)
  end

  # 1
  def zip_sort([l, r]), do: [Enum.sort(l), Enum.sort(r)]

  # 1
  def sum_distances([l, r]) do
    Enum.zip_reduce(l, r, 0, fn idl, idr, acc ->
      abs(idl - idr) + acc
    end)
  end

  # 2
  def similarity_score([l, r]) do
    freq = Enum.frequencies(r)

    Enum.reduce(l, 0, fn id, acc ->
      acc + Map.get(freq, id, 0) * id
    end)
  end
end

{:module, HistorianHysteria, <<70, 79, 82, 49, 0, 0, 13, ...>>, {:similarity_score, 1}}

import HistorianHysteria

puzzle_input
|> lists()
|> zip_sort()
|> sum_distances()

1319616

import HistorianHysteria

puzzle_input
|> lists()
|> similarity_score()

27267728