The diagram shows a restricted chess board with three black knights and three white knights. Your goal is to move the pieces so that the same squares are occupied but the colors are reversed. Your first move must use a black piece.
Pieces may move only as a normal chess knight, from one corner of a 2×3 rectangle to the opposite corner. No more than one piece may occupy a single square at a time. No piece may move onto a darkened square. No other rules of chess apply.
One turn is a sequence of moves made by a single piece. Find a solution with the minimum number of turns.
Here's one of 4 solutions that have 13 turns. It has 30 moves. That is the minimum number of turns found when checking for solutions of fewer than 32 moves.
The first move of a turn is marked with the turn number.
A4B2 1
E2C3 2
C3A4
B1C3 3
C3E2
E2D4
D5C3 4
C3B1
B4D5 5
D5C3
C3E2
B1C3 6
C3D5
D5B4
E2C3 7
C3D5
D2B1 8
B1C3
C3E2
D5C3 9
C3B1
B1D2
A4C3 10
C3B1
B2A4 11
A4C3
C3D5
E2C3 12
C3A4
D4E2 13

Posted by Charlie
on 20041211 02:00:37 