The numeric keyboards of a telephone (left) and a pocket calculator (right) differ in the arrangement of the keys.

123   789
456   456
789   123
  0      0

What is the least number of moves necessary to transfer the keys of the first arrangement into the other arrangement?
One move consists of switching the position of two neighbouring keys (Horizontal, vertical or diagonal) of which the sum is 9, 10 or 11.
Example: In the starting position you can switch 6 and 3, 5 and 6, 4 and 5, 7 and 4, 0 and 9

(In reply to uninterresting by traian)

I agree (except for the spelling).  I too was uninterested in this problem.  However I still feel it is a good problem.  Just because I am uninterested, doesn't make it a bad problem.  To me there are many factors that can go into rating a problem.  You may not have been suggesting anything as far as rating the problem, but I would hate anyone to rate a problem low because of disinterest, although I feel that is a factor.  And of course user ratings are opinion, and that is why they are averaged.  Blab, blab, blab.

Posted by john on 2005-07-07 16:08:03