Discussion on: AoC Day 8: Memory Maneuver

[Mustafa Haddara]

I liked this challenge a lot! It felt a lot more straightforward than the other problems.

The code came out extremely succinct, too, which is always nice. IMO it's quite readable:

Part 1:

function sum_metadata(input)
    nums = split(input, " ")
    result = total_for_node(nums)

    return result
end

function total_for_node(nums)
    num_children = parse(Int, popfirst!(nums))
    num_metadata = parse(Int, popfirst!(nums))
    total = 0
    for i in 1:num_children
        total += total_for_node(nums)
    end
    for i in 1:num_metadata
        meta = parse(Int, popfirst!(nums))
        total += meta
    end
    return total
end

Part 2 looks almost identical to part 1, but with an extra branch in the middle.

function sum_child(input)
    nums = split(input, " ")
    result = total_for_node(nums)[1]

    return result
end

function total_for_node(nums)
    num_children = parse(Int, popfirst!(nums))
    num_metadata = parse(Int, popfirst!(nums))
    all_childs = []
    for i in 1:num_children
        append!(all_childs, total_for_node(nums))
    end
    total = 0
    if length(all_childs) == 0
        for i in 1:num_metadata
            meta = parse(Int, popfirst!(nums))
            total += meta
        end
    else 
        for i in 1:num_metadata
            meta = parse(Int, popfirst!(nums))
            if meta <= length(all_childs)
                total += all_childs[meta]
            end
        end
    end
    return [total]
end