You have quarters laid out in the following pattern on the left and you want to move quarters to form the pattern on the right.

  Q      Q Q
 Q Q    Q   Q
Q Q Q    Q Q

Before| |After

The only rule is you must slide a coin without moving any others, such that the coin's ending location touches two other quarters. This means the following moves are illegal:

 A 1     Moving C to 1    
B C D 2  Moving B to 2  
 E F 

What is the shortest solution?

Move C and F as shown for the two-move solution:

A A C A C
B C to B to B D
D E F D E F E F

Posted by J. Alfred Prufrock Jr. on 2004-03-26 16:12:57