58 lines
1.2 KiB
Elixir
58 lines
1.2 KiB
Elixir
|
defmodule Aoc.Solution.Day04 do
|
||
|
|
import Aoc.Utils
|
||
|
|
|
||
|
|
@name "Day 4: Camp Cleanup"
|
||
|
|
@behaviour Solution
|
||
|
|
|
||
|
|
@impl Solution
|
||
|
|
def get_name, do: @name
|
||
|
|
|
||
|
|
@impl Solution
|
||
|
|
def present(solution), do: "#{solution} assignment pairs overlap"
|
||
|
|
|
||
|
|
@impl Solution
|
||
|
|
def present_again(solution), do: "Solution is #{solution}"
|
||
|
|
|
||
|
|
@impl Solution
|
||
|
|
def parse!(raw) do
|
||
|
|
raw
|
||
|
|
|> split_lines()
|
||
|
|
|> Enum.map(fn l -> parse_values(l, ",") end)
|
||
|
|
end
|
||
|
|
|
||
|
|
@impl Solution
|
||
|
|
def solve(pairs) do
|
||
|
|
pairs
|
||
|
|
|> ranges()
|
||
|
|
|> overlaps()
|
||
|
|
|> Enum.count()
|
||
|
|
end
|
||
|
|
|
||
|
|
@impl Solution
|
||
|
|
def solve_again(pairs) do
|
||
|
|
pairs
|
||
|
|
|> ranges()
|
||
|
|
|> strict_overlaps()
|
||
|
|
|> Enum.count()
|
||
|
|
end
|
||
|
|
|
||
|
|
def ranges(rows) when length(rows) > 2 do
|
||
|
|
Enum.map(rows, &ranges/1)
|
||
|
|
end
|
||
|
|
|
||
|
|
def ranges(pairs) do
|
||
|
|
Enum.map(pairs, fn p ->
|
||
|
|
[start, stop] = parse_values(p, "-") |> Enum.map(&String.to_integer/1)
|
||
|
|
MapSet.new(start..stop)
|
||
|
|
end)
|
||
|
|
end
|
||
|
|
|
||
|
|
def overlaps(ranges), do: Enum.filter(ranges, &overlap?/1)
|
||
|
|
|
||
|
|
def overlap?([a, b]), do: MapSet.subset?(a, b) or MapSet.subset?(b, a)
|
||
|
|
|
||
|
|
def strict_overlaps(ranges), do: Enum.filter(ranges, &strict_overlap?/1)
|
||
|
|
|
||
|
|
def strict_overlap?([a, b]), do: MapSet.intersection(a, b) |> Enum.count() > 0
|
||
|
|
end
|