I want all permutations of i. 4 for which 0 and 3 cannot be adjacent, nor can 1 and 2. My idea is to create a as follows to describe my situation.
]a =. 0 1 1 0,:i. 4 0 1 1 0 0 1 2 3 Next I created b and rotations on b to list the possibilities I can think of. So I can think of 6 permutations. Are there more and is there a better way to generate the real qualifying permutations? ]b =. 0 1 3 2 ,:1 0 2 3 0 1 3 2 1 0 2 3 1|."1 b 1 3 2 0 0 2 3 1 _1|."1 b 2 0 1 3 3 1 0 2 -- (B=) ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
