retrieving a specific row from array in LISP

[rahul...@gmail.com]

If we have following array
(setf *possible-die-combinations* (make-array '(20 6)
:initial-contents
'((1 3 2 4 5 6)
(1 2 4 5 3 6)
(1 4 5 3 2 6)
(1 5 3 2 4 6)
(2 3 6 4 1 5)
(2 6 4 1 3 5)
(2 4 1 3 6 5)
(2 1 3 6 4 5)
(3 5 6 2 1 4)
(3 6 2 1 5 4)
(3 2 1 5 6 4)
(3 1 5 6 2 4)
(4 6 5 1 2 3)
(4 5 1 2 6 3)
(4 1 2 6 5 3)
(4 2 6 5 1 3)
(5 3 1 4 6 2)
(5 1 4 6 3 2)
(5 4 6 3 1 2)
(5 6 3 1 4 2))))

If you would notice, in every row the set of first and second elements
together is unique. For e.g. the first row has (1, 3) and the second
row has (1, 2).
Now I want to retrieve a specific row based on this given combination
of first and second element. How do I do it?

[Pascal J. Bourguignon]

rahul...@gmail.com writes:

How do you do it?


(let ((f 1)
(s 4))
(find-if (lambda (row) (and (equal f (first row)) (equal s (second row))))
*possible-die-combinations*))

--
__Pascal Bourguignon__