Six pennies are arranged in the pattern of O's below.

    O O O
   O O O

Nearby pennies are touching. By the fewest number of legal moves, transform the pattern into the pattern

O O O O O O

consecutive pennies touching. A legal move consists of sliding a penny, not picking up a penny, without disturbing the other pennies, to a new position touching at least two pennies. (You might want to look up Moving Quarters for a similar problem with the same rules.)

It would be very easy to slide each of the top row to the lower, thereby being just 3 moves.

However, by reexamining the legal move criteria/criterion.
"A legal move consists of sliding a penny, without disturbing the other pennies,  to a new position touching at least two pennies.

For instance, I could legitimately move the middle coin of the top row to the right end of the lower row, but I MAYNOT move the one at the top right to the right end of the lower row.

I'm sure someone will beat me back with a solution.

Edited on June 5, 2005, 2:52 am

Posted by brianjn on 2005-06-03 03:30:05