All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Numbers
At Least Three Difference (Posted on 2010-08-04) Difficulty: 3 of 5
Place the numbers 1-9 in the boxes so that the difference of each pair of numbers joined by a line is at least three. The number 8 has already been placed.

No Solution Yet Submitted by Brian Smith    
Rating: 5.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Some Thoughts re: Computer solution: not just for 8 Comment 13 of 13 |
(In reply to Computer solution: not just for 8 by Charlie)


Initially you claimed  "The puzzle is solvable even when the 8 is replaced by 1, 2, 4 or 6."

Later you have added tHe digit 9, just providing 10 different solutions for the "extended" problem, rectifying a small error in your program.

Let me comment on the event.

In my opinion there is no better way of debugging a program than critically evaluate the final output , applying the basic "common sense" criteria.

In the case of the matrix abc,def,ghi, just by looking at the connectivity model  it is clear that e and f are interchangeable having the same neighbors.

Also ,for any found solution, replacing all its digits follOwing a (k==>10-k) transformation  we get a valid solution, i.e. there are 3 basic solutions:a1,a2,a4,and  they generate a9,a8,a6.

Those 6 represent 12 solution ,if exchanging the values in e and f counts as a new configuration.


I discovered the lack of symmetry immediately when your initial result was published but since you corrected it I did not react.

Now I  wrote about it just to emphasize the point I have mentioned above: ".. there is no better way of debugging a program than critically evaluate the final output".

No better remedy than common sense.



  Posted by Ady TZIDON on 2010-08-06 16:08:12
Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (4)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information