Day 8 Julia

using Combinatorics
data = collect.(readlines("input"))
diz = Dict{Char, Vector{Tuple{Int, Int}}}()
for (i, row) in enumerate(data), (j, c) in enumerate(row)
    (isdigit(c) || isletter(c)) && push!(get!(diz, c, []), (i, j))
end
checkbounds(x::Tuple{Int,Int})::Bool = 1 <= x[1] <= length(data[1]) && 1 <= x[2] <= length(data)

part1(data::Vector{Vector{Char}})::Int = begin
    v = Set{Tuple{Int, Int}}()
    for positions in values(diz)
        length(positions) > 1 && foreach(combinations(positions, 2)) do (a, b)
            diff = a .- b
            if diff[1]<0 || diff[2]<0
                checkbounds(a .+ diff) && push!(v, a .+ diff)
                checkbounds(b .- diff) && push!(v, b .- diff)
            else
                checkbounds(a .- diff) && push!(v, a .- diff)
                checkbounds(b .+ diff) && push!(v, b .+ diff)
            end
        end
    end
    length(v)
end

part2(data::Vector{Vector{Char}})::Int = begin
    v = Set{Tuple{Int, Int}}()
    for positions in values(diz)
        length(positions) > 1 && foreach(combinations(positions, 2)) do (a, b)
            diff = a .- b
            foreach(-div(50, maximum(abs.(diff)))-1:div(50, maximum(abs.(diff)))+1) do k
                x = a .+ k .* diff
                checkbounds(x) && push!(v, x)
            end
        end
    end
    length(v)
end

println(part1(data))
println(part2(data))