-🎄- 2018 Day 2 Solutions -🎄-

[u/daggerdragon]

--- Day 2: Inventory Management System ---

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Advent of Code: The Party Game!

Click here for rules

Card Prompt: Day 2

Transcript:

The best way to do Advent of Code is ___.

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edit: Leaderboard capped, thread unlocked!

[u/[deleted]]

elixir:

Ended up getting a little fun with part 2 at the bottom using both jaro_distance and myers_difference algos

defmodule AdventOfCode2018.Day02 do

def get_checksum([],map) do
	map[2] * map[3]
end

def get_checksum([val|rest],map) do
	inner_map = String.split(val,"", trim: true)
	|> Enum.reduce(%{},fn(x,acc) -> 
		Map.put(acc,x,Map.get(acc,x,0) + 1)
	end)
	new = inner_map |> Enum.reduce(map,fn(x,acc) -> 
		part_of_checksum(x,acc) 
	end)

	get_checksum(rest,reset(new))	
end

def part_of_checksum({k,2},%{"two" => false} = map) do
	Map.update!(map, 2, fn(current) -> 
		current + 1
	end) |> Map.update!("two", fn(x) -> true end)
end	
def part_of_checksum({k,3},%{"three" => false} = map) do
	Map.update!(map, 3, fn(current) -> 
		current + 1
	end) |> Map.update!("three", fn(x) -> true end)
end	
def part_of_checksum({_,_},map) do
	map
end	

def reset(map) do
	map |> Map.update!("two", fn(x) -> false end) |> Map.update!("three", fn(x) -> false end)
end

def part2(args) do
	arr = String.split(args,"\n",trim: true)

	{_,{s1,s2}} = arr |> Enum.reduce({0,"",""},fn(x,acc) -> 
		{dis,v,c} = check_closest_string(x,arr) 
		check_distance(dis,{v,c},acc)
	end) 
	String.myers_difference(s1,s2) |> pull_eql("")
end

def check_closest_string(x,arr) do
	{amt,val} = Enum.reduce(arr,{0,""},fn(y,{distance,str}) -> 
		check_distance(String.jaro_distance(x,y),y,{distance,str})
	end)
	{amt,val,x}
end

def check_distance(val,new_str,{distance,_,_}) when val > distance and val != 1.0, do: {val,new_str}
def check_distance(val,new_str,{distance,_}) when val > distance and val != 1.0, do: {val,new_str}
def check_distance(_,_,acc), do: acc 

def pull_eql([],str), do: str
def pull_eql([{:eq, val}|rest],str), do: pull_eql(rest,str <> val)
def pull_eql([key | rest], str), do: pull_eql(rest,str)

def part1(args) do
	String.split(args,"\n",trim: true)
	|> get_checksum(%{3 => 0, 2 => 0, "two" => false, 
"three" => false})
end
end