http://www.perlmonks.org?node_id=935597


in reply to Magic Squares Guessing

I would create a data-structure consisting of

Then you could use a recursive algorithm like the following:

  1. select an element from the number-list (*)
  2. select an empty position
  3. place the element at the position
  4. check, if the square is still consistent (all completely filled lines sum up to 175)
    • if yes, repeat the step with the new square and the reduced number-list
    • if no, restore the previous state (of number-list and square) and try with the next number and/or position
If the number-list is empty in step 1, you have found a solution.

Once you have your basic algorithm, you can optimize. E.g. your selection-algorithms and your consistency-checks. That's when the real fun starts :-) (because you can add "intelligence" instead of pure "brute-force")

Hope this helps! Rata

(*) a basic selection-algorithm could be going from first to last.