I have a few lists of items (which will likely but not necessarily have common elements). The lists are known to be sorted, but don't have a comparison function (they were manually put into the system in sorted order). I'd like to combine these lists into one list containing all the elements that is in a reasonable order given the existing ones.
Obviously there are edge cases and decisions to be made - I'm not too worried about the specifics, but rather I'd like a general approach to tackle the problem. Obviously if the two lists have nothing in common, there isn't much to be done besides appending one to the other, but that won't happen much.
As an example:
l1 = ['Task A', 'Task B', 'Task C', 'Task D'] l2 = ['Task B', 'Task B2', 'Task D', 'Task G'] l3 = ['Task A', 'Task C', 'Task E', 'Task D'] result = ['Task A', 'Task B', 'Task B2', 'Task C', 'Task E', 'Task D', 'Task G']
Again, I realize there is no perfect solution, and the output is not mission critical, I just want it to be reasonably nicely ordered in most cases. Any help would be appreciated.