There are six buttons in a row. Each button shows an arrow pointing left (L) or right (R). When you press a button, all buttons in the direction of its arrow (not including itself) rotate 180 degrees.

Find the least number of button presses required to get from RRRLLL to LRLRLR.

 >  >  >  <  <  <

[>] >  >  <  <  <  <-- (1)
 >  <  <  >  >  >

 >  <  <  > [>] >  <-- (2) 
 >  <  <  >  >  <

 >  < [<] >  >  <  <-- (3)
 <  >  <  >  >  <

 <  >  < [>] >  <  <-- (4)
 <  >  <  >  <  >

There are other [4] pressed button solutions.  Besides the
1, 5, 3, 4 solution as given above, there is the 5, 6, 1, 3 solution and may be more.

Edited on October 13, 2006, 8:28 am

Posted by Dej Mar on 2006-10-13 08:03:23