Find the Best and Worst Completion of a Partial Numeric Hand

## Problem Complete a partial numeric card hand to five cards, returning the strongest and weakest possible completed hands under the game rules below. Cards are digits `1` through `9`, repetitions are allowed, and every appended position may use any digit independently. ## Function Contract Implement `complete_hands(partial_hand)` and return `[best_hand, worst_hand]`. Each result is a five-character string that begins with `partial_hand`. ## Rules - Categories from strongest to weakest are: five of a kind, four of a kind, full house, two pair, three of a kind, one pair, high card. - Classify a hand by multiplicities only; there are no suits, straights, or flushes. - Within the same category, compare the original five card positions from right to left; at the first difference, the larger digit is stronger. - If `partial_hand` already has length 5, return that hand as both the best and worst completion. - Use an extensible object-oriented category-evaluator abstraction so adding a category does not require rewriting `complete_hands` or the shared comparison flow. ## Constraints - `0 <= len(partial_hand) <= 5`. - Every character in `partial_hand` is a digit from `1` through `9`. - There are at most `9^5` possible full hands, but avoid duplicating category and tie-break logic between the best and worst searches. ## Examples ```text partial_hand = "99" output = ["99999", "99321"] ``` `"99999"` is five of a kind. Because the fixed prefix already contains a pair, one pair is the weakest attainable category; `"99321"` is the weakest such completion under the right-to-left tie-break.