# Day 16
```elixir
Mix.install([
{:kino, "~> 0.6.2"}
])
```
## Input
```elixir
input = Kino.Input.textarea("In put here:")
```
<!-- livebook:{"reevaluate_automatically":true} -->
```elixir
data =
input
|> Kino.Input.read()
|> Base.decode16!()
```
```elixir
defmodule Bits do
def apply_operation(op, data) do
IO.puts("Performing op #{op} on #{inspect(data)}")
case op do
0 -> Enum.sum(data)
1 -> Enum.product(data)
2 -> Enum.min(data)
3 -> Enum.max(data)
5 -> if(Enum.at(data, 0) > Enum.at(data, 1), do: 1, else: 0)
6 -> if(Enum.at(data, 0) < Enum.at(data, 1), do: 1, else: 0)
7 -> if(Enum.at(data, 0) == Enum.at(data, 1), do: 1, else: 0)
_ -> :error
end
end
def parse(<<version::3, id::3, payload::bits>>) when id == 4 do
IO.puts("Parsing literal ver #{version}")
with {data, rest} <- parse_payload(payload) do
size = bit_size(data)
<<val::integer-unsigned-size(size)>> = data
IO.puts("Value: #{inspect(val)} ")
{[val], version, rest}
end
end
def parse(<<version::3, id::3, 1::1, num::11, rest::bits>>) do
IO.puts("Ver #{version}, id #{id}, length #{num} packes ")
{data, ver, rem} =
for _i <- 1..num,
reduce: {[], version, rest} do
{data, vsum, rest} ->
# IO.puts("#{i} / #{num}, rest: #{inspect(rest)}")
{c, ver, rem} = parse(rest)
{data ++ c, ver + vsum, rem}
end
{[apply_operation(id, data)], ver, rem}
end
def parse(<<version::3, id::3, 0::1, length::15, rest::bits>>) do
IO.puts("Ver #{version}, id #{id}, length #{length} bits ")
<<payload::size(length), unparsed::bits>> = rest
{data, ver, <<>>} = parse_sequence(<<payload::size(length)>>)
{[apply_operation(id, data)], version + ver, unparsed}
end
def parse_sequence(data) do
{data, ver, remaining} = parse(data)
case remaining do
<<>> ->
{data, ver, <<>>}
_ ->
{rest_data, rest_ver, rest_rem} = parse_sequence(remaining)
{data ++ rest_data, ver + rest_ver, rest_rem}
end
end
def parse_payload(<<1::1, bits::4, rest::bits>>) do
with {rest_parsed, rest_unparsed} = parse_payload(rest) do
# |> IO.inspect(label: "literal")
{<<bits::4, rest_parsed::bits>>, rest_unparsed}
end
end
def parse_payload(<<0::1, bits::4, rest::bits>>), do: {<<bits::4>>, rest}
end
```
## Part 1
<!-- livebook:{"reevaluate_automatically":true} -->
```elixir
Bits.parse(data)
```
