# Advent of Code - Day 05
```elixir
Mix.install([
{:kino_aoc, git: "https://github.com/ljgago/kino_aoc"}
])
```
## Advent of Code Helper
<!-- livebook:{"attrs":{"day":"5","session_secret":"SESSION_ID","variable":"puzzle_input","year":"2022"},"kind":"Elixir.KinoAOC.HelperCell","livebook_object":"smart_cell"} -->
```elixir
{:ok, puzzle_input} = KinoAOC.download_puzzle("2022", "5", System.fetch_env!("LB_SESSION_ID"))
```
<!-- livebook:{"branch_parent_index":0} -->
## Part One
-> Description Part One
<!-- livebook:{"break_markdown":true} -->
### Code
```elixir
defmodule PartOne do
def resolve(input) do
IO.puts("--- Part One ---")
IO.puts("Result: #{run(input)}")
end
def run(input) do
[crates_and_ids, actions] = String.split(input, "\n\n")
actions =
actions
|> String.split("\n", trim: true)
|> Enum.map(fn action ->
~r"move ([0-9]+) from ([1-9]) to ([1-9])"
|> Regex.scan(action)
|> Enum.map(fn [_, count, from, to] ->
{String.to_integer(count), String.to_integer(from), String.to_integer(to)}
end)
end)
crates =
crates_and_ids
|> String.split("\n")
# Remove the ids as I don't need it
|> Enum.drop(-1)
|> Enum.map(fn str ->
str
|> String.split("")
# `[A] ` are 4 chars
|> Enum.chunk_every(4, 4, [""])
|> Enum.map(fn str ->
str
|> Enum.join("")
|> String.replace(["[", "]"], "")
|> String.trim()
end)
# Pad the list with the same number of
|> then(fn list ->
l = length(list)
n = 10
if l == n, do: list, else: list ++ List.duplicate("", n - l)
end)
end)
|> Enum.zip()
|> Enum.map(fn crate ->
crate
|> Tuple.to_list()
|> Enum.filter(&(&1 != ""))
end)
Enum.reduce(actions, crates, fn [{count, from, to}], crates ->
{move, from_crate} =
crates
|> Enum.at(from - 1)
|> Enum.split(count)
to_crate = Enum.reverse(move) ++ Enum.at(crates, to - 1)
crates
|> List.replace_at(from - 1, from_crate)
|> List.replace_at(to - 1, to_crate)
end)
|> Enum.map(&Enum.take(&1, 1))
|> Enum.join("")
end
end
```
### Tests
```elixir
ExUnit.start(autorun: false)
defmodule PartOneTest do
use ExUnit.Case, async: true
import PartOne
test "part one" do
input = """
[D]
[N] [C]
[Z] [M] [P]
1 2 3
move 1 from 2 to 1
move 3 from 1 to 3
move 2 from 2 to 1
move 1 from 1 to 2
"""
result = run(input)
assert result == "CMZ"
end
end
ExUnit.run()
```
### Solution
```elixir
PartOne.resolve(puzzle_input)
```
---
<!-- livebook:{"branch_parent_index":0} -->
## Part Two
-> Description Part Two
<!-- livebook:{"break_markdown":true} -->
### Code
```elixir
defmodule PartTwo do
def resolve(input) do
IO.puts("--- Part One ---")
IO.puts("Result: #{run(input)}")
end
def run(input) do
[crates_and_ids, actions] = String.split(input, "\n\n")
actions =
actions
|> String.split("\n", trim: true)
|> Enum.map(fn action ->
~r"move ([0-9]+) from ([1-9]) to ([1-9])"
|> Regex.scan(action)
|> Enum.map(fn [_, count, from, to] ->
{String.to_integer(count), String.to_integer(from), String.to_integer(to)}
end)
end)
crates =
crates_and_ids
|> String.split("\n")
# Remove the ids as I don't need it
|> Enum.drop(-1)
|> Enum.map(fn str ->
str
|> String.split("")
# `[A] ` are 4 chars
|> Enum.chunk_every(4, 4, [""])
|> Enum.map(fn str ->
str
|> Enum.join("")
|> String.replace(["[", "]"], "")
|> String.trim()
end)
# Pad the list with the same number of
|> then(fn list ->
l = length(list)
n = 10
if l == n, do: list, else: list ++ List.duplicate("", n - l)
end)
end)
|> Enum.zip()
|> Enum.map(fn crate ->
crate
|> Tuple.to_list()
|> Enum.filter(&(&1 != ""))
end)
Enum.reduce(actions, crates, fn [{count, from, to}], crates ->
{move, from_crate} =
crates
|> Enum.at(from - 1)
|> Enum.split(count)
# Step 1: Enum.reverse(move)
# Step 2: move
to_crate = move ++ Enum.at(crates, to - 1)
crates
|> List.replace_at(from - 1, from_crate)
|> List.replace_at(to - 1, to_crate)
end)
|> Enum.map(&Enum.take(&1, 1))
|> Enum.join("")
end
end
```
### Tests
```elixir
ExUnit.start(autorun: false)
defmodule PartTwoTest do
use ExUnit.Case, async: true
import PartTwo
test "part two" do
input = """
[D]
[N] [C]
[Z] [M] [P]
1 2 3
move 1 from 2 to 1
move 3 from 1 to 3
move 2 from 2 to 1
move 1 from 1 to 2
"""
result = run(input)
assert result == "MCD"
end
end
ExUnit.run()
```
### Solution
```elixir
PartTwo.resolve(puzzle_input)
```
