adventofcode/2021/day2/day2.erl

-module(day2).

-export ([solve/0, solve/1, solve/2]).

solve() ->
    solve(['1']),
    solve(['2']),
    init:stop().

solve(A) ->
    solve(A, get_data()).

solve(['1'], D) ->
    io:format("The solution to ~p puzzle1 is: ~p~n", [?MODULE, solve(1, D)]);
solve(1, D) ->
    solution1(D);
solve(['2'], D) ->
    io:format("The solution to ~p puzzle2 is: ~p~n", [?MODULE, solve(2, D)]);
solve(2, D) ->
    solution2(D).

solution1(D) ->
    {X, Y} =
    lists:foldl(fun({Dir, Dis}, {X, Y}) ->
        case Dir of
            'up' -> {X, Y - Dis};
            'down' -> {X, Y + Dis};
            'forward' -> {X + Dis, Y}
        end
        end,
   {0, 0},
   D),
   X * Y.

solution2(D) ->
    {X, Y, _} =
    lists:foldl(fun({Dir, Dis}, {X, Y, Aim}) ->
        case Dir of
            'up' -> {X, Y, Aim - Dis};
            'down' -> {X, Y, Aim + Dis};
            'forward' -> {X + Dis, Y + (Dis * Aim), Aim}
        end
        end,
   {0,0,0},
   D),
   X * Y.

get_data() ->
[
{forward, 3},
{down, 4},
{forward, 3},
{up, 4},
{down, 4},
{down, 6},
{down, 3},
{down, 1},
{up, 7},
{down, 7},
{forward, 4},
{forward, 7},
{forward, 3},
{down, 2},
{forward, 5},
{down, 7},
{forward, 5},
{up, 9},
{down, 6},
{forward, 8},
{forward, 8},
{down, 8},
{forward, 7},
{down, 9},
{down, 4},
{down, 6},
{forward, 1},
{down, 2},
{down, 7},
{up, 4},
{forward, 8},
{down, 5},
{down, 7},
{down, 1},
{forward, 5},
{down, 1},
{up, 1},
{forward, 5},
{forward, 1},
{down, 1},
{forward, 3},
{up, 4},
{up, 4},
{up, 8},
{up, 1},
{forward, 7},
{down, 3},
{forward, 3},
{forward, 3},
{down, 3},
{down, 6},
{down, 7},
{forward, 4},
{down, 2},
{up, 3},
{forward, 5},
{forward, 1},
{down, 3},
{up, 3},
{up, 4},
{forward, 2},
{forward, 6},
{up, 1},
{down, 9},
{up, 3},
{forward, 5},
{forward, 2},
{up, 9},
{up, 2},
{down, 5},
{down, 5},
{forward, 7},
{forward, 1},
{down, 7},
{forward, 9},
{forward, 8},
{down, 7},
{forward, 5},
{forward, 4},
{down, 5},
{forward, 7},
{forward, 3},
{down, 2},
{forward, 2},
{forward, 2},
{down, 1},
{up, 8},
{down, 2},
{down, 2},
{forward, 6},
{up, 9},
{forward, 6},
{up, 6},
{forward, 5},
{forward, 5},
{down, 2},
{forward, 5},
{up, 5},
{forward, 5},
{up, 4},
{down, 1},
{up, 5},
{down, 2},
{forward, 3},
{down, 1},
{forward, 2},
{up, 4},
{down, 6},
{forward, 1},
{forward, 6},
{forward, 6},
{forward, 8},
{forward, 8},
{forward, 3},
{forward, 5},
{down, 8},
{up, 8},
{down, 6},
{down, 8},
{forward, 8},
{down, 6},
{forward, 4},
{down, 4},
{forward, 7},
{forward, 9},
{down, 6},
{up, 6},
{forward, 6},
{down, 9},
{up, 7},
{up, 9},
{down, 1},
{up, 5},
{forward, 2},
{forward, 3},
{up, 6},
{forward, 8},
{forward, 7},
{down, 4},
{up, 8},
{up, 2},
{down, 2},
{up, 3},
{down, 2},
{down, 8},
{forward, 9},
{up, 9},
{forward, 7},
{down, 9},
{forward, 4},
{forward, 3},
{forward, 2},
{down, 5},
{forward, 3},
{forward, 1},
{down, 2},
{forward, 3},
{down, 7},
{down, 8},
{forward, 9},
{down, 9},
{forward, 2},
{up, 5},
{up, 2},
{down, 8},
{down, 1},
{down, 7},
{forward, 6},
{down, 2},
{forward, 9},
{down, 6},
{down, 9},
{forward, 9},
{down, 2},
{up, 5},
{forward, 2},
{down, 7},
{down, 6},
{up, 1},
{forward, 9},
{up, 7},
{down, 1},
{forward, 5},
{down, 5},
{up, 2},
{forward, 6},
{forward, 2},
{up, 9},
{up, 7},
{down, 2},
{down, 1},
{forward, 6},
{down, 2},
{forward, 9},
{forward, 8},
{forward, 2},
{up, 1},
{down, 7},
{down, 7},
{forward, 5},
{forward, 9},
{down, 5},
{down, 5},
{down, 5},
{forward, 4},
{up, 4},
{down, 7},
{up, 6},
{forward, 3},
{up, 5},
{forward, 3},
{forward, 6},
{forward, 8},
{down, 6},
{forward, 4},
{forward, 5},
{up, 8},
{down, 9},
{down, 3},
{down, 8},
{forward, 8},
{forward, 1},
{down, 7},
{down, 2},
{forward, 8},
{forward, 7},
{up, 2},
{down, 9},
{forward, 2},
{down, 6},
{down, 7},
{up, 2},
{up, 7},
{down, 6},
{down, 8},
{down, 2},
{forward, 8},
{down, 6},
{up, 1},
{down, 6},
{down, 5},
{down, 8},
{down, 1},
{down, 4},
{down, 1},
{down, 8},
{up, 3},
{forward, 1},
{forward, 5},
{forward, 2},
{forward, 2},
{down, 5},
{down, 2},
{down, 8},
{up, 7},
{forward, 2},
{forward, 1},
{forward, 4},
{up, 4},
{down, 5},
{up, 4},
{down, 8},
{up, 5},
{down, 6},
{down, 8},
{down, 8},
{forward, 8},
{forward, 5},
{down, 1},
{down, 2},
{down, 4},
{forward, 5},
{up, 3},
{forward, 3},
{down, 7},
{forward, 9},
{down, 9},
{down, 5},
{forward, 5},
{down, 9},
{forward, 9},
{down, 5},
{up, 4},
{up, 9},
{forward, 1},
{forward, 6},
{forward, 9},
{forward, 2},
{up, 5},
{forward, 9},
{down, 8},
{up, 2},
{up, 9},
{forward, 1},
{down, 7},
{down, 4},
{down, 4},
{up, 3},
{forward, 6},
{down, 1},
{forward, 6},
{forward, 3},
{up, 3},
{forward, 1},
{down, 1},
{up, 8},
{up, 3},
{forward, 9},
{forward, 1},
{forward, 8},
{forward, 8},
{up, 7},
{forward, 2},
{forward, 9},
{down, 9},
{down, 2},
{down, 5},
{down, 1},
{forward, 9},
{forward, 9},
{up, 4},
{forward, 6},
{down, 3},
{forward, 2},
{forward, 5},
{up, 4},
{forward, 2},
{up, 1},
{up, 4},
{up, 3},
{up, 6},
{up, 6},
{down, 2},
{up, 7},
{down, 1},
{down, 3},
{forward, 3},
{up, 5},
{forward, 4},
{down, 5},
{forward, 9},
{down, 2},
{up, 5},
{forward, 9},
{down, 3},
{down, 5},
{forward, 3},
{forward, 7},
{forward, 9},
{up, 2},
{down, 6},
{up, 6},
{down, 8},
{forward, 8},
{down, 1},
{forward, 3},
{forward, 4},
{up, 6},
{up, 3},
{forward, 6},
{forward, 5},
{forward, 2},
{down, 7},
{down, 1},
{down, 5},
{forward, 6},
{down, 4},
{down, 2},
{forward, 7},
{up, 9},
{forward, 3},
{down, 2},
{up, 3},
{down, 3},
{down, 1},
{up, 5},
{down, 4},
{forward, 1},
{forward, 2},
{forward, 2},
{forward, 6},
{forward, 2},
{down, 2},
{down, 8},
{down, 1},
{down, 2},
{down, 7},
{up, 7},
{down, 7},
{forward, 7},
{forward, 7},
{down, 8},
{forward, 1},
{down, 7},
{down, 7},
{down, 8},
{up, 9},
{down, 4},
{up, 6},
{forward, 7},
{up, 2},
{down, 8},
{forward, 2},
{down, 8},
{forward, 4},
{down, 4},
{forward, 4},
{up, 1},
{down, 2},
{forward, 6},
{forward, 7},
{forward, 8},
{down, 2},
{forward, 5},
{forward, 1},
{up, 9},
{down, 8},
{down, 2},
{forward, 1},
{down, 8},
{forward, 2},
{up, 2},
{up, 3},
{up, 7},
{forward, 3},
{forward, 3},
{up, 3},
{up, 5},
{forward, 8},
{down, 6},
{forward, 6},
{down, 2},
{down, 7},
{forward, 3},
{forward, 6},
{down, 5},
{down, 6},
{up, 4},
{forward, 8},
{up, 8},
{down, 9},
{forward, 7},
{forward, 1},
{down, 6},
{up, 1},
{down, 7},
{forward, 4},
{forward, 8},
{down, 2},
{forward, 8},
{down, 3},
{down, 5},
{down, 5},
{forward, 8},
{down, 3},
{up, 8},
{down, 9},
{forward, 2},
{down, 9},
{forward, 4},
{up, 8},
{forward, 4},
{up, 1},
{forward, 8},
{forward, 2},
{forward, 5},
{down, 2},
{down, 6},
{up, 2},
{down, 8},
{forward, 9},
{forward, 5},
{forward, 6},
{forward, 4},
{down, 4},
{down, 6},
{up, 1},
{forward, 3},
{down, 6},
{forward, 6},
{forward, 1},
{forward, 6},
{forward, 9},
{up, 6},
{forward, 5},
{down, 4},
{forward, 5},
{down, 8},
{down, 7},
{forward, 7},
{up, 5},
{down, 6},
{forward, 4},
{forward, 6},
{forward, 5},
{up, 4},
{down, 3},
{forward, 1},
{down, 1},
{forward, 6},
{up, 1},
{up, 1},
{down, 7},
{forward, 5},
{forward, 1},
{down, 2},
{forward, 2},
{down, 3},
{down, 6},
{down, 5},
{down, 4},
{forward, 2},
{forward, 1},
{down, 7},
{forward, 9},
{up, 6},
{forward, 9},
{forward, 2},
{down, 1},
{forward, 9},
{forward, 4},
{down, 1},
{forward, 3},
{up, 9},
{down, 1},
{down, 3},
{down, 6},
{down, 9},
{forward, 3},
{down, 8},
{down, 3},
{forward, 5},
{forward, 1},
{forward, 5},
{forward, 2},
{up, 4},
{down, 6},
{up, 7},
{forward, 7},
{down, 9},
{forward, 6},
{down, 4},
{down, 1},
{up, 8},
{down, 4},
{forward, 7},
{forward, 5},
{down, 5},
{down, 2},
{down, 1},
{down, 4},
{up, 5},
{down, 8},
{forward, 1},
{forward, 2},
{down, 9},
{forward, 7},
{down, 8},
{forward, 5},
{forward, 7},
{forward, 2},
{down, 6},
{down, 5},
{down, 6},
{down, 7},
{forward, 2},
{up, 9},
{down, 3},
{forward, 1},
{up, 6},
{forward, 4},
{down, 3},
{up, 7},
{forward, 9},
{forward, 7},
{down, 4},
{up, 1},
{forward, 6},
{up, 4},
{down, 1},
{down, 4},
{down, 2},
{down, 5},
{down, 4},
{down, 7},
{forward, 2},
{down, 8},
{down, 8},
{forward, 9},
{forward, 3},
{down, 2},
{down, 2},
{forward, 2},
{down, 9},
{forward, 8},
{up, 8},
{down, 3},
{forward, 4},
{down, 9},
{up, 2},
{forward, 6},
{forward, 2},
{up, 6},
{up, 7},
{forward, 1},
{forward, 2},
{up, 2},
{down, 8},
{forward, 9},
{down, 7},
{forward, 1},
{down, 6},
{down, 8},
{forward, 2},
{down, 8},
{forward, 6},
{forward, 7},
{forward, 8},
{forward, 1},
{up, 8},
{down, 5},
{forward, 8},
{down, 3},
{down, 6},
{forward, 6},
{down, 4},
{down, 6},
{forward, 8},
{down, 3},
{down, 4},
{forward, 6},
{forward, 1},
{up, 1},
{up, 3},
{forward, 7},
{forward, 2},
{down, 1},
{down, 7},
{down, 3},
{down, 4},
{down, 3},
{forward, 2},
{forward, 4},
{down, 6},
{down, 2},
{forward, 3},
{down, 9},
{down, 5},
{down, 6},
{down, 7},
{down, 5},
{down, 3},
{forward, 5},
{forward, 6},
{down, 3},
{down, 1},
{up, 3},
{down, 8},
{down, 7},
{down, 5},
{up, 9},
{down, 8},
{down, 4},
{down, 2},
{forward, 4},
{forward, 9},
{forward, 1},
{forward, 7},
{down, 3},
{down, 4},
{up, 9},
{down, 6},
{forward, 9},
{down, 4},
{down, 2},
{down, 5},
{down, 3},
{forward, 2},
{forward, 9},
{forward, 3},
{down, 5},
{up, 1},
{down, 9},
{forward, 9},
{down, 7},
{forward, 6},
{down, 6},
{down, 9},
{down, 7},
{down, 8},
{down, 2},
{up, 3},
{forward, 6},
{forward, 3},
{up, 4},
{down, 6},
{down, 8},
{down, 2},
{down, 1},
{up, 9},
{down, 1},
{down, 8},
{forward, 5},
{forward, 4},
{forward, 9},
{forward, 3},
{forward, 9},
{down, 5},
{up, 9},
{down, 6},
{forward, 4},
{down, 6},
{forward, 4},
{forward, 9},
{down, 7},
{up, 9},
{up, 2},
{forward, 5},
{forward, 6},
{up, 2},
{forward, 8},
{down, 6},
{forward, 8},
{forward, 1},
{forward, 2},
{forward, 6},
{down, 3},
{up, 2},
{forward, 7},
{up, 8},
{forward, 2},
{forward, 5},
{forward, 4},
{up, 6},
{forward, 9},
{up, 8},
{down, 3},
{up, 7},
{up, 2},
{down, 2},
{up, 4},
{up, 5},
{forward, 5},
{down, 9},
{forward, 2},
{down, 1},
{down, 6},
{down, 4},
{down, 1},
{down, 1},
{forward, 4},
{forward, 7},
{down, 4},
{down, 2},
{forward, 7},
{down, 4},
{up, 1},
{up, 8},
{down, 6},
{down, 8},
{forward, 6},
{down, 8},
{up, 2},
{down, 7},
{forward, 5},
{forward, 8},
{down, 9},
{forward, 1},
{up, 7},
{down, 5},
{up, 1},
{up, 6},
{down, 3},
{down, 4},
{down, 9},
{down, 6},
{forward, 1},
{down, 1},
{forward, 4},
{down, 4},
{down, 8},
{up, 1},
{down, 7},
{forward, 1},
{down, 6},
{down, 4},
{down, 5},
{forward, 6},
{forward, 8},
{down, 5},
{down, 5},
{up, 3},
{forward, 8},
{down, 4},
{down, 3},
{up, 1},
{up, 8},
{forward, 1},
{down, 6},
{down, 2},
{down, 6},
{down, 1},
{forward, 9},
{down, 1},
{forward, 6},
{forward, 9},
{down, 5},
{up, 4},
{down, 5},
{down, 1},
{forward, 2},
{down, 2},
{forward, 9},
{down, 3},
{forward, 7},
{forward, 8},
{forward, 5},
{down, 7},
{down, 6},
{down, 8},
{forward, 7},
{up, 7},
{forward, 6},
{forward, 3},
{down, 2},
{forward, 9},
{forward, 4},
{down, 6},
{down, 6},
{up, 9},
{down, 1},
{forward, 5},
{forward, 2},
{forward, 2},
{forward, 2},
{down, 8},
{up, 1},
{down, 4},
{forward, 3},
{down, 3},
{up, 4},
{down, 6},
{forward, 2},
{forward, 8},
{forward, 9},
{forward, 3},
{down, 4},
{forward, 2},
{forward, 5},
{down, 5},
{up, 8},
{up, 9},
{up, 3},
{forward, 9},
{forward, 3},
{forward, 3},
{forward, 8},
{forward, 2},
{forward, 7},
{down, 8},
{down, 6},
{forward, 6},
{forward, 8},
{down, 1},
{forward, 3},
{down, 7},
{forward, 5},
{forward, 3},
{forward, 3},
{down, 3},
{down, 5},
{down, 2},
{down, 6},
{up, 2},
{up, 7},
{down, 9},
{forward, 6},
{down, 9},
{down, 8},
{up, 8},
{down, 1},
{forward, 9},
{down, 8},
{forward, 7},
{forward, 6},
{down, 5},
{down, 7},
{down, 4},
{forward, 7},
{down, 8},
{down, 9},
{down, 4},
{up, 8},
{forward, 2},
{up, 6},
{forward, 6},
{forward, 3},
{forward, 6},
{up, 9},
{forward, 1},
{down, 3},
{up, 6},
{down, 8},
{up, 4},
{up, 5},
{forward, 8},
{forward, 5},
{forward, 3},
{forward, 3},
{forward, 4},
{down, 4},
{forward, 2},
{up, 2},
{down, 7},
{down, 5},
{forward, 7},
{down, 8},
{forward, 3},
{up, 5},
{down, 4},
{down, 1},
{down, 5},
{forward, 6},
{forward, 8},
{forward, 6},
{down, 2},
{down, 7},
{forward, 6},
{forward, 2},
{forward, 7},
{down, 5},
{forward, 2},
{forward, 7},
{down, 9},
{down, 9},
{down, 4},
{down, 7},
{down, 3},
{forward, 1},
{up, 8},
{down, 7},
{forward, 2},
{forward, 4},
{up, 2},
{forward, 2},
{down, 2},
{up, 2},
{up, 9},
{forward, 1},
{down, 5},
{down, 1},
{forward, 8},
{up, 3},
{up, 4},
{down, 3},
{up, 2},
{down, 8},
{down, 6},
{down, 4},
{up, 7},
{forward, 4},
{down, 7},
{down, 4},
{up, 3},
{up, 8},
{down, 1},
{down, 7},
{forward, 1},
{down, 2},
{forward, 6},
{down, 9},
{forward, 3},
{down, 9},
{up, 5},
{up, 1},
{down, 4},
{forward, 1},
{down, 4},
{forward, 4},
{up, 4},
{forward, 7},
{down, 9},
{down, 2},
{down, 8},
{forward, 2},
{up, 3},
{forward, 2},
{down, 7},
{forward, 8},
{forward, 6},
{forward, 1},
{up, 9},
{forward, 7},
{up, 4},
{down, 4},
{down, 3},
{down, 7},
{forward, 5},
{forward, 3},
{forward, 7}
].