68 lines
1.3 KiB
Elixir
68 lines
1.3 KiB
Elixir
defmodule Day2 do
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def read_program do
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File.read!("lib/day2/input.txt")
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|> String.trim()
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|> String.split(",")
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|> Enum.map(&String.to_integer/1)
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end
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def part1 do
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read_program()
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|> List.replace_at(1, 12)
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|> List.replace_at(2, 2)
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|> run()
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end
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def part2 do
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base_prog = read_program()
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Enum.each(0..99, fn a ->
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Enum.each(0..99, fn b ->
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res =
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base_prog
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|> List.replace_at(1, a)
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|> List.replace_at(2, b)
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|> run()
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if Enum.at(res, 0) == 19_690_720 do
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IO.inspect(100 * a + b)
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end
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end)
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end)
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end
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def run(memory, ip \\ 0)
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def run(memory, ip) when ip < length(memory) do
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case eval(Enum.drop(memory, ip), memory) do
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{:halt, memory} ->
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memory
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{:cont, memory, offset} ->
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run(memory, ip + offset)
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end
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end
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def run(memory, _ip), do: memory
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def eval([99 | _], memory) do
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{:halt, memory}
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end
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def eval([1, a, b, dest | _], memory) do
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{
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:cont,
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List.replace_at(memory, dest, Enum.at(memory, a) + Enum.at(memory, b)),
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4
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}
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end
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def eval([2, a, b, dest | _], memory) do
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{
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:cont,
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List.replace_at(memory, dest, Enum.at(memory, a) * Enum.at(memory, b)),
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4
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}
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end
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end
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