A : 1
B : 2	C : 3	D : 4
E : 5	F : 6	G : 7
	H : 8

Arrange the numbers in the grid above in such a way that no two adjecent cells (horizontally, vertically or diagonally) have consecutive number in them. For example 1 must not be next to 2. (The letters are shown so that you can easily refer to specific individual boxes.)

(From: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml)

8 and 1 have to go in the middle for this to work. So F:8, C:1. Obviously 2 and 7 must now go in H and A respectively. then it's simply a matter of triangulation. 3 and 4 are the vertices of the triangle with respect to 2, i.e. E:4, G:3. and 5 and 6 with respect to 8, so D:5, B:6. You could mirror these as well, switching 1 & 8 and moving things accordingly. And/Or the 5,6 can switch as long as you also switch the 4,3 at the same time.

A:2
B:6 C:8 D:5
E:4 F:1 G:3
H:7

The solution above saves properly with A and H centered, but then when I look at the comment, the A is over B and H over 7. That is NOT part of my solution. It's just the way this things handles white space, I suppose.
Edited on September 2, 2003, 4:33 pm
Edited on September 2, 2003, 4:35 pm

Posted by Lawrence on 2003-09-02 16:32:34