Fifteen dominoes have been arranged in a 5x6 grid below. The '==' and '!' represent fault lines in the arrangement. A fault line is a straight line going all the way through the arrangement without hitting any of the dominoes.

Rearrange the dominoes so that there are no fault lines in the grid.

+--+--+--+--+--+--+
|     !  |  |  |  |
+--+--+  +  +  +  +
|     !  |  |  |  |
+==+==+==+==+==+==+
|  |  !  |     |  |
+  +  +  +--+--+  +
|  |  !  |     |  |
+==+==+==+==+==+==+
|     !     |     |
+--+--+--+--+--+--+

Arrived at by playing with actual dominoes:

+--+--+--+--+--+--+
|  |     |  |     |
+  +--+--+  +--+--+
|  |     |  |  |  |
+--+--+--+--+  +  +
|  |  !     |  |  |
+  +  +--+--+--+--+
|  |  |  |     |  |
+--+--+  +--+--+  +
|     |  |     |  |
+--+--+--+--+--+--+

Posted by Charlie on 2005-12-18 17:02:55