gleam

    
import gleam/dict
import gleam/io
import gleam/list
import gleam/option.{None, Some}
import gleam/result
import gleam/set.{type Set}
import gleam/string
import simplifile

pub type Point =
  #(Int, Int)

pub type Grid(a) =
  dict.Dict(Point, a)

pub type Direction {
  North
  East
  South
  West
}

pub type Loops {
  DoesLoop
  DoesNotLoop
}

pub type Guard {
  Guard(position: Point, direction: Direction)
}

fn get_guard(grid: Grid(String)) -> Guard {
  let pos = dict.filter(grid, fn(_pos, char) { char == "^" })
  let assert Ok(pos) = case dict.size(pos) {
    1 -> list.first(dict.keys(pos))
    0 -> panic as "No guard found in input!"
    _ -> panic as "More than one guard found in input!"
  }
  Guard(pos, North)
}

fn move_guard(guard: Guard) -> Guard {
  let new_pos = case guard.direction {
    North -> #(-1, 0)
    East -> #(0, 1)
    South -> #(1, 0)
    West -> #(0, -1)
  }
  Guard(
    #(guard.position.0 + new_pos.0, guard.position.1 + new_pos.1),
    guard.direction,
  )
}

fn turn_guard(guard: Guard) -> Guard {
  let new_dir = case guard.direction {
    North -> East
    East -> South
    South -> West
    West -> North
  }
  Guard(guard.position, new_dir)
}

fn get_obstacles(grid: Grid(String)) -> List(Point) {
  dict.filter(grid, fn(_pos, char) { char == "#" })
  |> dict.keys()
}

fn recurse_grid(
  grid: Grid(String),
  guard: Guard,
  obstacles: List(#(Int, Int)),
  visited: Set(#(#(Int, Int), Direction)),
) -> #(Set(#(#(Int, Int), Direction)), Loops) {
  let new_guard = move_guard(guard)
  let position = new_guard.position
  let dir = new_guard.direction
  case dict.has_key(grid, position) {
    False -> #(visited, DoesNotLoop)
    True -> {
      case set.contains(visited, #(position, dir)) {
        True -> {
          #(visited, DoesLoop)
        }
        False -> {
          case list.contains(obstacles, position) {
            True -> recurse_grid(grid, turn_guard(guard), obstacles, visited)
            False ->
              recurse_grid(
                grid,
                new_guard,
                obstacles,
                set.insert(visited, #(position, dir)),
              )
          }
        }
      }
    }
  }
}

fn get_grid_input(filename: String) -> Grid(String) {
  let lines =
    filename
    |> simplifile.read()
    |> result.unwrap("")
    |> string.trim()
    |> string.split("\n")
  use grid, row, row_idx <- list.index_fold(lines, dict.new())
  use grid, col, col_idx <- list.index_fold(string.to_graphemes(row), grid)
  dict.insert(grid, #(row_idx, col_idx), col)
}

fn part_one(
  grid: Grid(String),
) -> #(#(Set(#(#(Int, Int), Direction)), Loops), Int) {
  let guard = get_guard(grid)
  let obstacles = get_obstacles(grid)
  let visited = set.new() |> set.insert(#(guard.position, guard.direction))
  let visited = recurse_grid(grid, guard, obstacles, visited)
  let visited_without_dir =
    set.fold(visited.0, set.new(), fn(acc, x) { set.insert(acc, x.0) })
  #(visited, visited_without_dir |> set.size())
}

fn check_loop(grid: Grid(String), blocker: Point) -> Loops {
  let blocked_grid =
    dict.upsert(grid, blocker, fn(x) {
      case x {
        Some("^") -> "^"
        Some(_) -> "#"
        None -> "#"
      }
    })
  let visited = part_one(blocked_grid).0
  visited.1
}

fn part_two(grid: Grid(String), visited: Set(#(#(Int, Int), Direction))) {
  let visited =
    set.fold(visited, set.new(), fn(acc, x) { set.insert(acc, x.0) })
  use counter, position <- set.fold(visited, 0)
  case check_loop(grid, position) {
    DoesLoop -> counter + 1
    DoesNotLoop -> counter
  }
}

pub fn main() {
  let input = "input.in"
  let p1 = input |> get_grid_input() |> part_one
  let visited = p1.0.0
  io.debug(p1.1)
  input |> get_grid_input |> part_two(visited) |> io.debug()
}

  

 gleam

    
import gleam/int
import gleam/io
import gleam/list
import gleam/regex
import gleam/result
import gleam/string
import simplifile

pub fn main() {
  let assert Ok(data) = simplifile.read("input.in")
  part_one(data) |> io.debug
  part_two(data) |> io.debug
}

fn part_one(data) {
  let assert Ok(multiplication_pattern) =
    regex.from_string("mul\\(\\d{1,3},\\d{1,3}\\)")
  let assert Ok(digit_pattern) = regex.from_string("\\d{1,3},\\d{1,3}")
  let multiplications =
    regex.scan(multiplication_pattern, data)
    |> list.flat_map(fn(reg) {
      regex.scan(digit_pattern, reg.content)
      |> list.map(fn(digits) {
        digits.content
        |> string.split(",")
        |> list.map(fn(x) { x |> int.parse |> result.unwrap(0) })
        |> list.reduce(fn(a, b) { a * b })
        |> result.unwrap(0)
      })
    })
    |> list.reduce(fn(a, b) { a + b })
    |> result.unwrap(0)
}

fn part_two(data) {
  let data = "do()" <> string.replace(data, "\n", "") <> "don't()"
  let assert Ok(pattern) = regex.from_string("do\\(\\).*?don't\\(\\)")
  regex.scan(pattern, data)
  |> list.map(fn(input) { input.content |> part_one })
  |> list.reduce(fn(a, b) { a + b })
}

  

 elixir

    
defmodule Day02 do
  defp part1(reports) do
    reports
    |> Enum.map(fn report ->
      levels =
        report
        |> String.split()
        |> Enum.map(&String.to_integer/1)

      cond do
        sequence_is_safe?(levels) ->
          :safe

        true ->
          :unsafe
      end
    end)
    |> Enum.count(fn x -> x == :safe end)
  end

  defp part2(reports) do
    reports
    |> Enum.map(fn report ->
      levels =
        report
        |> String.split()
        |> Enum.map(&String.to_integer/1)

      sequences =
        0..(length(levels) - 1)
        |> Enum.map(fn i ->
          List.delete_at(levels, i)
        end)

      cond do
        sequence_is_safe?(levels) ->
          :safe

        Enum.any?(sequences, &sequence_is_safe?/1) ->
          :safe

        true ->
          :unsafe
      end
    end)
    |> Enum.count(fn x -> x == :safe end)
  end

  defp all_gaps_within_max_diff?(numbers) do
    numbers
    |> Enum.chunk_every(2, 1, :discard)
    |> Enum.all?(fn [a, b] -> abs(b - a) <= 3 end)
  end

  defp is_strictly_increasing?(numbers) do
    numbers
    |> Enum.chunk_every(2, 1, :discard)
    |> Enum.all?(fn [a, b] -> a < b end)
  end

  defp is_strictly_decreasing?(numbers) do
    numbers
    |> Enum.chunk_every(2, 1, :discard)
    |> Enum.all?(fn [a, b] -> a > b end)
  end

  defp sequence_is_safe?(numbers) do
    (is_strictly_increasing?(numbers) or
       is_strictly_decreasing?(numbers)) and all_gaps_within_max_diff?(numbers)
  end

  def run(data) do
    reports = data |> String.split("\n", trim: true)
    p1 = part1(reports)
    p2 = part2(reports)
    IO.puts(p1)
    IO.puts(p2)
  end
end

data = File.read!("input.in")
Day02.run(data)

  

 elixir

    
part_one =
  File.read!("input.in")
  |> String.split("\n", trim: true)
  |> Enum.map(fn line ->
    line
    |> String.split()
    |> Enum.map(&String.to_integer/1)
  end)
  |> Enum.reduce({[], []}, fn [first, second], {list1, list2} ->
    {[first | list1], [second | list2]}
  end)
  |> then(fn {list1, list2} ->
    {Enum.sort(list1), Enum.sort(list2)}
  end)
  |> then(fn {list1, list2} ->
    Enum.zip(list1, list2)
    |> Enum.map(fn {x, y} -> abs(x - y) end)
  end)
  |> Enum.sum()

part_two =
  File.read!("input.in")
  |> String.split("\n", trim: true)
  |> Enum.map(fn line ->
    line
    |> String.split()
    |> Enum.map(&String.to_integer/1)
  end)
  |> Enum.reduce({[], []}, fn [first, second], {list1, list2} ->
    {[first | list1], [second | list2]}
  end)
  |> then(fn {list1, list2} ->
    Enum.map(list1, fn line ->
      line * Enum.count(list2, fn x -> x === line end)
    end)
    |> Enum.sum()
  end)

IO.inspect(part_one)
IO.inspect(part_two)

  

 http get https://api.github.com/orgs/golang/repos

    
| get license.key -i
| uniq --count
| rename license

This outputs the following:

╭───┬──────────────┬───────╮
│ # │    license   │ count │
├───┼──────────────┼───────┤
│ 0 │ bsd-3-clause │    23 │
│ 1 │ apache-2.0   │     5 │
│ 2 │              │     2 │
╰───┴──────────────┴───────╯