gistfile1.txt

;; -*- coding:utf-8 -*-

(use gauche.sequence)
(use util.match)
(use util.combinations)
(use srfi-197)                          ;chain

(define (num-fingers hands)
  (define (f hand) (case hand
                     [(グー) 0]
                     [(チョキ) 2]
                     [(パー) 5]))
  (apply + (map f hands)))

(define (num-winners hands)
  (match (delete-duplicates hands)
    [('グー 'チョキ) (count (cut eq? <> 'グー) hands)]
    [('グー 'パー) (count (cut eq? <> 'パー) hands)]
    [('チョキ 'パー) (count (cut eq? <> 'チョキ) hands)]
    [_ 0]))

(define (all-decisive-hands)
  (chain (concatenate (make-list 6 '(グー チョキ パー)))
         (combinations* _ 6)
         (filter-map (^[hands] (let1 n (num-winners hands)
                                 (and (> n 0)
                                      (list (num-fingers hands)
                                            (num-winners hands))))) _)
         (sort _ < car)
         (delete-neighbor-dups _)))

gistfile2.txt

gosh> (all-decisive-hands)
((2 5) (4 4) (5 1) (6 3) (8 2) (10 2) (10 1) (15 3) (15 5) (18 4) (20 4) (21 3)
 (24 2) (25 5) (27 1))