Set consolidation: Difference between revisions

Original solution:

{{trans|Racket}}

<lang txr>@(do

(defun mkset (items) [group-by identity items])

(defun empty-p (set) (zerop (hash-count set)))

(defun consoli (ss)

(defun comb (cs s)

(cond ((empty-p s) cs)

((null cs) (list s))

((empty-p (hash-isec s (first cs)))

(cons (first cs) (comb (rest cs) s)))

(t (consoli (cons (hash-uni s (first cs)) (rest cs))))))

[reduce-left comb nil ss])

;; tests

(each ((test '(((a b) (c d))

((a b) (b d))

((a b) (c d) (d b))

((h i k) (a b) (c d) (d b) (f g h)))))

(format t "~s -> ~s\n" test

[mapcar hash-keys (consoli [mapcar mkset test])])))</lang>

Output:

<pre>((a b) (c d)) -> ((b a) (d c))

((a b) (b d)) -> ((b a) (b d))

((a b) (c d) (d b)) -> ((b a) (d c) (b d))

((h i k) (a b) (c d) (d b) (f g h)) -> ((k i h) (b a) (d c) (b d) (g f h))</pre>