2023.04

Q1: 20407
Q1 completed in 0.988ms
Q2: 23806951
Q2 completed in 1.419ms

challenges/2023/04.exs

@@ -0,0 +1,64 @@
+Code.compile_file(Path.join([__ENV__.file], ["../../../utils/utils.exs"]))
+
+defmodule Challenge do
+  @moduledoc false
+
+  def first_result(input) do
+    input
+    |> parse_cards()
+    |> Enum.reduce(0, fn {[winning, own], _idx}, acc ->
+      won = get_num_of_won_numbers(winning, own)
+      2 |> :math.pow(won - 1) |> trunc() |> Kernel.+(acc)
+    end)
+  end
+
+  def second_result(input) do
+    cards = parse_cards(input)
+    number_of_cards = length(cards)
+    copies = Enum.reduce(cards, %{}, fn {_card, idx}, acc -> Map.put(acc, idx, 1) end)
+
+    cards
+    |> Enum.reduce(copies, fn {[winning, own], idx}, current_copies ->
+      case get_num_of_won_numbers(winning, own) do
+        won when won >= 1 ->
+          num_of_copies = Map.get(current_copies, idx)
+
+          Enum.reduce(1..won, current_copies, fn idx_diff, acc ->
+            case idx + idx_diff do
+              copy_idx when copy_idx < number_of_cards ->
+                Map.put(acc, copy_idx, Map.get(acc, copy_idx) + num_of_copies)
+
+              _ ->
+                acc
+            end
+          end)
+
+        _ ->
+          current_copies
+      end
+    end)
+    |> Enum.reduce(0, &(elem(&1, 1) + &2))
+  end
+
+  defp get_num_of_won_numbers(winning_nums, own_nums) do
+    Enum.reduce(own_nums, 0, fn num, acc ->
+      if num in winning_nums, do: acc + 1, else: acc
+    end)
+  end
+
+  defp parse_cards(input) do
+    input
+    |> Enum.with_index()
+    |> Enum.map(fn {card, card_idx} ->
+      card
+      |> String.split(": ")
+      |> List.last()
+      |> String.split(" | ")
+      |> Enum.map(&String.split(&1, " ", trim: true))
+      |> then(&{&1, card_idx})
+    end)
+  end
+end
+
+Utils.run(&Challenge.first_result/1, __ENV__.file, "Q1")
+Utils.run(&Challenge.second_result/1, __ENV__.file, "Q2")

challenges/2023/04.js

@@ -0,0 +1,52 @@
+// Part 1
+const solvePuzzle1 = (input) => {
+  const lines = input.split('\n').map((line) => {
+    const [winning, own] = line
+      .split(': ')[1]
+      .split(' | ')
+      .map((nums) => nums.split(' ').filter((n) => n !== ''));
+
+    let hit = 0;
+
+    own.forEach((num) => {
+      if (winning.includes(num)) {
+        hit += 1;
+      }
+    });
+
+    const cardValue = Math.pow(2, hit - 1);
+    return cardValue >= 1 ? cardValue : 0;
+  });
+  return lines.reduce((acc, num) => acc + num, 0);
+};
+
+// Part 2
+const solvePuzzle2 = (input) => {
+  const cards = input.split('\n').map((line) =>
+    line
+      .split(': ')[1]
+      .split(' | ')
+      .map((nums) => nums.split(' ').filter((n) => n !== ''))
+  );
+
+  const copies = cards.map((_) => 1);
+
+  cards.forEach(([winning, own], idx) => {
+    let hit = 0;
+
+    own.forEach((num) => {
+      if (winning.includes(num)) {
+        hit += 1;
+      }
+    });
+
+    for (let j = 0; j < hit && idx + j + 1 < copies.length; j++) {
+      copies[idx + j + 1] += copies[idx];
+    }
+  });
+
+  return copies.reduce((acc, num) => acc + num, 0);
+};
+
+require(__dirname + '/../../utils/test.js').test(__filename, __dirname, solvePuzzle1, '1');
+require(__dirname + '/../../utils/test.js').test(__filename, __dirname, solvePuzzle2, '2');