+--+--+--+--+--+
|  |  |  |  |11|     
+--+--+--+--+--+
|  |  |  |  |  |     
+--+--+--+--+--+
|  |  |  |  |  |     
+--+--+--+--+--+
| 5|  |  |19|  |     
+--+--+--+--+--+
|  |  |  |  |  |     
+--+--+--+--+--+

A hound started on a square numbered 1, and moved from square to square numbering them in succession to the last one, numbered 25. The hound never entered any square twice and moved horizontally and vertically only, except for one diagonal move to a neighboring square.

All the numbers except those shown were then deleted. Figure out the path of the hound.

The path from 5 to 11 must contain a diagonal (otherwise you simply can't get there).  This also "walls" off the upper left corner, implying that the number 1-4 appear there.  With no diagonals left to use, 25 must then appear in the lower left corner.

Posted by Bryan on 2013-06-27 12:55:39