108 lines
2.2 KiB
Elixir
108 lines
2.2 KiB
Elixir
defmodule AOCHelpers.Grid do
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import AOCHelpers
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defstruct [:map, :bounds]
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def to_grid(str) do
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lists =
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str
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|> lines()
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|> Enum.map(&letters/1)
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map =
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for {list, y} <- Enum.with_index(lists), {v, x} <- Enum.with_index(list), into: %{} do
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{{x, y}, v}
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end
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max_x =
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map
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|> Enum.map(fn {{x, _}, _} -> x end)
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|> Enum.max()
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max_y =
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map
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|> Enum.map(fn {{_, y}, _} -> y end)
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|> Enum.max()
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bounds = {0..max_x, 0..max_y}
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%__MODULE__{map: map, bounds: bounds}
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end
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def in_bounds?(%__MODULE__{bounds: {min_x..max_x, min_y..max_y}}, {x, y}) do
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min_x <= x and x <= max_x and min_y <= y and y <= max_y
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end
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def update!(grid, coords, value) do
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%__MODULE__{grid | map: Map.update!(grid.map, coords, value)}
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end
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def get(grid, coords, default \\ nil) do
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Map.get(grid.map, coords, default)
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end
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def map(grid, fun) do
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map =
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Enum.map(grid.map, fn {coords, value} ->
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{coords, fun.(value)}
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end)
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|> Enum.into(%{})
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%__MODULE__{grid | map: map}
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end
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def inspect(%__MODULE__{map: map, bounds: bounds}) do
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{xs, ys} = bounds
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for y <- ys, into: "" do
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line =
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for x <- xs, into: "" do
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Map.get(map, {x, y}, " ")
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end
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"#{line}\n"
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end
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|> IO.puts()
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end
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def find_value(grid, value) do
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with {coords, _} <- Enum.find(grid.map, fn {_, v} -> v == value end) do
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coords
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end
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end
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def find(grid, fun) do
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Enum.find(grid.map, fn {_, v} -> fun.(v) end)
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end
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def neighbors(grid, coords, diag? \\ false) do
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coords
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|> neighbor_coords()
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|> Enum.filter(fn {c, dirs} ->
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if diag? do
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in_bounds?(grid, c)
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else
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in_bounds?(grid, c) and length(dirs) == 1
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end
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end)
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|> Enum.map(fn {c, dirs} ->
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{c, dirs, Map.get(grid.map, c)}
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end)
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end
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defp neighbor_coords({x, y}) do
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for {j, j_dir} <- [{y - 1, [:north]}, {y, []}, {y + 1, [:south]}],
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{i, i_dir} <- [{x - 1, [:west]}, {x, []}, {x + 1, [:east]}],
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{x, y} != {i, j} do
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{{i, j}, j_dir ++ i_dir}
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end
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end
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end
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# defimpl Inspect, for: AOCHelpers.Grid do
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# import Inspect.Algebra
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# def inspect(grid, opts) do
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# end
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# end
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