Combinitoric mess

gistfile1.txt

function clone(s)
   local t = {}
   for k, v in pairs(s) do
      t[k] = v
   end
   return t
end


-- Generate all possible combinations, then filter
-- Reasonably horrible runtime but I want it offline and for a set of 4 so it's not a problem
local i = 0
function Combo(t, filter, output, count)

   output = output or {}
   count = count or #t

   if count == 0 then
       table.sort(output)
       filter[table.concat(output)] = true
       return
   end


   for k, v in ipairs(t) do
        local myoutput = clone(output)
        table.insert(myoutput, v)
        Combo(t, filter, myoutput, count - 1)
   end

end

f = {}
Combo({'a', 'b', 'c', 'd'}, f)

-- Fancy formatter
local final = {}
for k, v in pairs(f) do
    table.insert(final, k)
end
table.sort(final)
for k, v in ipairs(final) do
    print(k, v)
end