commit 1a18bd1bb7d4793f99b6b86b814b33307be91160 · hauleth.dev/advent-of-code

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2022/day14.livemd
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       <!-- livebook:{"persist_outputs":true} -->

     

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       # Day 14

     

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       ```elixir

     

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       Mix.install(

     

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         [

     

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           {:kino_aoc, git: "https://github.com/ljgago/kino_aoc"},

     

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           :image

     

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         ],

     

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         consolidate_protocols: false

     

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       )

     

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       ```

     

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       <!-- livebook:{"output":true} -->

     

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       ```

     

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       :ok

     

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       ```

     

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       ## Setup

     

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       <!-- livebook:{"attrs":{"day":"14","session_secret":"ADVENT_OF_CODE_SESSION","variable":"puzzle_input","year":"2022"},"kind":"Elixir.KinoAOC.HelperCell","livebook_object":"smart_cell"} -->

     

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       ```elixir

     

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       {:ok, puzzle_input} =

     

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         KinoAOC.download_puzzle("2022", "14", System.fetch_env!("LB_ADVENT_OF_CODE_SESSION"))

     

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       ```

     

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       <!-- livebook:{"output":true} -->

     

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       ```

     

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       {:ok,

     

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        "492,26 -> 492,17 -> 492,26 -> 494,26 -> 494,16 -> 494,26 -> 496,26 -> 496,22 -> 496,26 -> 498,26 -> 498,17 -> 498,26 -> 500,26 -> 500,20 -> 500,26 -> 502,26 -> 502,25 -> 502,26 -> 504,26 -> 504,23 -> 504,26 -> 506,26 -> 506,21 -> 506,26 -> 508,26 -> 508,16 -> 508,26 -> 510,26 -> 510,24 -> 510,26\n481,92 -> 481,96 -> 476,96 -> 476,99 -> 487,99 -> 487,96 -> 485,96 -> 485,92\n460,73 -> 460,70 -> 460,73 -> 462,73 -> 462,69 -> 462,73 -> 464,73 -> 464,65 -> 464,73 -> 466,73 -> 466,65 -> 466,73 -> 468,73 -> 468,64 -> 468,73 -> 470,73 -> 470,68 -> 470,73 -> 472,73 -> 472,68 -> 472,73\n470,76 -> 470,80 -> 466,80 -> 466,84 -> 481,84 -> 481,80 -> 474,80 -> 474,76\n492,26 -> 492,17 -> 492,26 -> 494,26 -> 494,16 -> 494,26 -> 496,26 -> 496,22 -> 496,26 -> 498,26 -> 498,17 -> 498,26 -> 500,26 -> 500,20 -> 500,26 -> 502,26 -> 502,25 -> 502,26 -> 504,26 -> 504,23 -> 504,26 -> 506,26 -> 506,21 -> 506,26 -> 508,26 -> 508,16 -> 508,26 -> 510,26 -> 510,24 -> 510,26\n495,155 -> 499,155\n460,73 -> 460,70 -> 460,73 -> 462,73 -> 462,69 -> 462,73 -> 464,73 -> 464,65 -> 464,73 -> 466,73 -> 466,65 -> 466,73 -> 468,73 -> 468,64 -> 468,73 -> 470,73 -> 470,68 -> 470,73 -> 472,73 -> 472,68 -> 472,73\n500,138 -> 505,138\n484,39 -> 484,38 -> 484,39 -> 486,39 -> 486,33 -> 486,39 -> 488,39 -> 488,30 -> 488,39 -> 490,39 -> 490,35 -> 490,39 -> 492,39 -> 492,38 -> 492,39 -> 494,39 -> 494,30 -> 494,39 -> 496,39 -> 496,36 -> 496,39\n481,92 -> 481,96 -> 476,96 -> 476,99 -> 487,99 -> 487,96 -> 485,96 -> 485,92\n492,26 -> 492,17 -> 492,26 -> 494,26 -> 494,16 -> 494,26 -> 496,26 -> 496,22 -> 496,26 -> 498,26 -> 498,17 -> 498,26 -> 500,26 -> 500,20 -> 500,26 -> 502,26 -> 502,25 -> 502,26 -> 504,26 -> 504,23 -> 504,26 -> 506,26 -> 506,21 -> 506,26 -> 508,26 -> 508,16 -> 508,26 -> 510,26 -> 510,24 -> 510,26\n460,73 -> 460,70 -> 460,73 -> 462,73 -> 462,69 -> 462,73 -> 464,73 -> 464,65 -> 464,73 -> 466,73 -> 466,65 -> 466,73 -> 468,73 -> 468,64 -> 468,73 -> 470,73 -> 470,68 -> 470,73 -> 472,73 -> 472,68 -> 472,73\n492,26 -> 492,17 -> 492,26 -> 494,26 -> 494,16 -> 494,26 -> 496,26 -> 496,22 -> 496,26 -> 498,26 -> 498,17 -> 498,26 -> 500,26 -> 500,20 -> 500,26 -> 502,26 -> 502,25 -> 502,26 -> 504,26 -> 504,23 -> 504,26 -> 506,26 -> 506,21 -> 506,26 -> 508,26 -> 508,16 -> 508,26 -> 510,26 -> 510,24 -> 510,26\n460,73 -> 460,70 -> 460,73 -> 462,73 -> 462,69 -> 462,73 -> 464,73 -> 464,65 -> 464,73 -> 466,73 -> 466,65 -> 466,73 -> 468,73 -> 468,64 -> 468,73 -> 470,73 -> 470,68 -> 470,73 -> 472,73 -> 472,68 -> 472,73\n492,26 -> 492,17 -> 492,26 -> 494,26 -> 494,16 -> 494,26 -> 496,26 -> 496,22 -> 496,26 -> 498,26 -> 498,17 -> 498,26 -> 500,26 -> 500,20 -> 500,26 -> 502,26 -> 502,25 -> 502,26 -> 504,26 -> 504,23 -> 504,26 -> 506,26 -> 506,21 -> 506,26 -> 508,26 -> 508,16 -> 508,26 -> 510,26 -> 510,24 -> 510,26\n489,115 -> 489,119 -> 481,119 -> 481,126 -> 494,126 -> 494,119 -> 493,119 -> 493,115\n492,26 -> 492,17 -> 492,26 -> 494,26 -> 494,16 -> 494,26 -> 496,26 -> 496,22 -> 496,26 -> 498,26 -> 498,17 -> 498,26 -> 500,26 -> 500,20 -> 500,26 -> 502,26 -> 502,25 -> 502,26 -> 504,26 -> 504,23 -> 504,26 -> 506,26 -> 506,21 -> 506,26 -> 508,26 -> 508,16 -> 508,26 -> 510,26 -> 510,24 -> 510,26\n485,112 -> 485,102 -> 485,112 -> 487,112 -> 487,111 -> 487,112 -> 489,112 -> 489,105 -> 489,112\n481,92 -> 481,96 -> 476,96 -> 476,99 -> 487,99 -> 487,96 -> 485,96 -> 485,92\n484,39 -> 484,38 -> 484,39 -> 486,39 -> 486,33 -> 486,39 -> 488,39 -> 488,30 -> 488,39 -> 490,39 -> 490,35 -> 490,39 -> 492,39 -> 492,38 -> 492,39 -> 494,39 -> 494,30 -> 494,39 -> 496,39 -> 496,36 -> 496,39\n470,49 -> 470,53 -> 468,53 -> 468,60 -> 477,60 -> 477,53 -> 476,53 -> 476,49\n483,160 -> 487,160\n492,26 -> 492,17 -> 492,26 -> 494,26 -> 494,16 -> 494,26 -> 496,26 -> 496,22 -> 496,26 -> 498,26 -> 498,17 -> 498,26 -> 500,26 -> 500,20 -> 500,26 -> 502,26 -> 502,25 -> 502,26 -> 504,26 -> 504,23 -> 504,26 -> 506,26 -> 506,21 -> 506,26 -> 508,26 -> 508,16 -> 508,26 -> 510,26 -> 510,24 -> 510,26\n460,73 -> 460,70 -> 460,73 -> 462,73 -> 462,69 -> 462,73 -> 464,73 -> 464,65 -> 464,73 -> 466,73 -> 466,65 -> 466,73 -> 468,73 -> 468,64 -> 468,73 -> 47" <> ...}

     

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       ```

     

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       ```elixir

     

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       defmodule Cave do

     

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         defstruct map: MapSet.new(), occupied: MapSet.new(), width: nil, height: 0, start: {500, 0}

     

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         def parse(input, start \\ {500, 0}) do

     

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           map =

     

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             input

     

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             |> String.split("\n", trim: true)

     

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             |> Enum.map(&Cave.parse_line/1)

     

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             |> Enum.reduce(&MapSet.union/2)

     

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           {width, height} =

     

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             for {x, y} <- map,

     

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                 reduce: {nil, nil} do

     

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               {nil, nil} ->

     

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                 {x..x, y}

     

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               {min_x..max_x, max_y} ->

     

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                 {min(min_x, x)..max(max_x, x), max(max_y, y)}

     

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             end

     

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           %__MODULE__{map: map, occupied: map, start: start, width: width, height: height}

     

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         end

     

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         def add_line(%__MODULE__{} = cave, line) do

     

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           {width, height} =

     

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             Enum.reduce(line, {cave.width, cave.height}, fn {x, y}, {x0..x1, h} ->

     

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               {min(x, x0)..max(x, x1), max(y, h)}

     

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             end)

     

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           struct(cave,

     

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             width: width,

     

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             height: height,

     

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             map: MapSet.union(cave.map, line),

     

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             occupied: MapSet.union(cave.occupied, line)

     

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           )

     

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         end

     

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         def parse_point(str) do

     

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           [x, y] = String.split(str, ",")

     

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           {String.to_integer(x), String.to_integer(y)}

     

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         end

     

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         def parse_line(line) do

     

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           points =

     

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             line

     

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             |> String.split(" -> ")

     

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             |> Enum.map(&parse_point/1)

     

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             |> Enum.chunk_every(2, 1, :discard)

     

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             |> Enum.flat_map(fn

     

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               [{x, y1}, {x, y2}] ->

     

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                 for y <- y1..y2, do: {x, y}

     

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               [{x1, y}, {x2, y}] ->

     

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                 for x <- x1..x2, do: {x, y}

     

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             end)

     

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             |> MapSet.new()

     

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           points

     

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         end

     

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         def drop_sand(%__MODULE__{} = cave), do: drop_sand(cave, cave.start)

     

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         def drop_sand(%__MODULE__{height: h, width: x0..x1} = cave, {sx, sy})

     

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             when sx not in x0..x1 or sy >= h,

     

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             do: {:fall_out, cave}

     

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         def drop_sand(%__MODULE__{} = cave, {sx, sy}) do

     

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           cond do

     

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             {sx, sy + 1} not in cave.occupied -> drop_sand(cave, {sx, sy + 1})

     

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             {sx - 1, sy + 1} not in cave.occupied -> drop_sand(cave, {sx - 1, sy + 1})

     

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             {sx + 1, sy + 1} not in cave.occupied -> drop_sand(cave, {sx + 1, sy + 1})

     

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             true -> {{sx, sy}, struct(cave, occupied: MapSet.put(cave.occupied, {sx, sy}))}

     

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           end

     

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         end

     

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       end

     

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       defimpl Kino.Render, for: Cave do

     

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         def to_livebook(%@for{} = cave) do

     

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           x0..x1 = cave.width

     

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           {sx, sy} = cave.start

     

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           image = Image.new!(x1 - x0 + 3, cave.height + 3)

     

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           {:ok, image} =

     

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             Image.mutate(image, fn im ->

     

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               Image.Draw.point(im, sx - x0 + 1, sy + 1, color: :red)

     

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               for {x, y} <- cave.occupied do

     

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                 Image.Draw.point(im, x - x0 + 1, y + 1, color: :tan)

     

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               end

     

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               for {x, y} <- cave.map do

     

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                 Image.Draw.point(im, x - x0 + 1, y + 1, color: :white)

     

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               end

     

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               :ok

     

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             end)

     

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           buf =

     

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             image

     

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             |> Image.resize!(4, interpolate: :nearest)

     

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             |> Image.write!(:memory, suffix: ".png")

     

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           Kino.Output.image(buf, "image/png")

     

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         end

     

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       end

     

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       ```

     

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       <!-- livebook:{"output":true} -->

     

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       ```

     

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       {:module, Kino.Render.Cave, <<70, 79, 82, 49, 0, 0, 16, ...>>, {:to_livebook, 1}}

     

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       ```

     

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       ```elixir

     

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       cave = Cave.parse(puzzle_input)

     

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       ```

     

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       ## Task 1

     

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       ```elixir

     

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       Stream.unfold(cave, &Cave.drop_sand/1)

     

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       |> Enum.take_while(&(&1 != :fall_out))

     

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       |> length()

     

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       ```

     

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       <!-- livebook:{"output":true} -->

     

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       ```

     

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       768

     

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       ```

     

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       ## Task 2

     

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       ```elixir

     

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       floor_y = cave.height + 2

     

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       floor = for x <- 0..(cave.width.last * 2), into: MapSet.new(), do: {x, floor_y}

     

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       cave = Cave.add_line(cave, floor)

     

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       Stream.unfold(cave, &Cave.drop_sand/1)

     

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       |> Enum.take_while(&(&1 != cave.start))

     

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       |> length()

     

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       |> then(&(&1 + 1))

     

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       ```

     

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       <!-- livebook:{"output":true} -->

     

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       ```

     

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       26686

     

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       ```