require "table2"

local function gen_sequence(ones, num_zeros)
    if #ones == 0 then return {string.rep("0", num_zeros)} end
    local result = {}
    for x = 1, num_zeros - #ones + 1 do
        local skip_one = ones:slice(2)
        for gen_sequence(skip_one, num_zeros - x) as tail do
            result:insert(string.rep("0", x) .. ones[1] .. tail)
        end
    end
    return result
end

local function print_block(data, len)
    local a = data:split("")
    local sum_bytes = 0
    if #a > 0 then sum_bytes = table.sum(a:mapped(|c| -> c:byte() - 48)) end
    print($"\nblocks \{{a:concat(", ")}}, cells {len}")
    if len - sum_bytes <= 0 then
        print("No solution")
        return
    end
    local prep = a:mapped(|c| -> string.rep("1", c:byte() - 48))
    for gen_sequence(prep, len - sum_bytes + 1) as r do
        print(r:sub(2))
    end
end

print_block("21", 5)
print_block("", 5)
print_block("8", 10)
print_block("2323", 15)
print_block("23", 5)