Add 2015 Day 2

This commit is contained in:
Adam Millerchip 2023-09-02 02:01:44 +09:00
parent b788fa1096
commit 6eee6cace0

66
2015/day2.exs Normal file
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defmodule Day2 do
def part1(input) do
input
|> Enum.map(fn [x, y, z] ->
a = x * y
b = x * z
c = y * z
min = Enum.min([a, b, c])
2 * (a + b + c) + min
end)
|> Enum.sum()
end
def part2(input) do
input
|> Enum.map(fn box ->
[x, y, z] = Enum.sort(box)
2 * (x + y) + x * y * z
end)
|> Enum.sum()
end
def input do
with [input_filename] <- System.argv(),
{:ok, input} <- File.read(input_filename) do
input
|> String.split(["\n", "x"], trim: true)
|> Enum.map(&String.to_integer/1)
|> Enum.chunk_every(3)
else
_ -> :error
end
end
#######################
# HERE BE BOILERPLATE #
#######################
def run do
case input() do
:error -> print_usage()
input -> run_parts_with_timer(input)
end
end
defp run_parts_with_timer(input) do
run_with_timer(1, fn -> part1(input) end)
run_with_timer(2, fn -> part2(input) end)
end
defp run_with_timer(part, fun) do
{time, result} = :timer.tc(fun)
IO.puts("Part #{part} (completed in #{format_time(time)}):\n")
IO.puts("#{result}\n")
end
defp format_time(μsec) when μsec < 1_000, do: "#{μsec}μs"
defp format_time(μsec) when μsec < 1_000_000, do: "#{μsec / 1000}ms"
defp format_time(μsec), do: "#{μsec / 1_000_000}s"
defp print_usage do
IO.puts("Usage: elixir day2.exs input_filename")
end
end
Day2.run()