Java-Gaming.org Hi !
Featured games (83)
games approved by the League of Dukes
Games in Showcase (523)
Games in Android Showcase (127)
games submitted by our members
Games in WIP (592)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
 
    Home     Help   Search   Login   Register   
Pages: [1]
  ignore  |  Print  
  3x3 Magic Square Backtracking recursively?  (Read 2223 times)
0 Members and 1 Guest are viewing this topic.
Offline Shane75776
« Posted 2012-04-17 20:55:32 »

I have this pseudo-code that I am supposed to use to come up with the coded algorithm
for filling a 3x3 Magic Square. I can't seem to grasp my head around this pseudo code
for some reason. Could somebody help me with this?

pseudo-code
1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
12  
13  
recursive_funtion(position) {
    for number from 1 to 9, not used elsewhere already {
       put this number on this position, make it unavailable
       if solution valid {
          if solution complete {
              done, show solution
           }else{
              recursive_function(next_position)
          }
       }
       (make this space blank again, and the number available)
       }
}


My code so far (Completely wrong im sure)
1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
int[][] square = new int[3][3];
   ArrayList<Integer> used_nums = new ArrayList<Integer>();
   
   
   public MagicSquare()
   {
      rec_backtrack(0);
      print_square();
   }
   public void rec_backtrack(int level)
   {
      int step = 0;
      for(int i = 1; i < 10; i++)
      {
         if(!used_nums.contains(i))
         {
            square[step][level] = i;
            used_nums.add(i);
            step++;
         }
         if(step == 3) //we have inserted to all 3 spots now, check for solution
         {
            if((square[0][level] + square[1][level] + square[2][level]) == 15) //acceptable solution
            {
               rec_backtrack(level++);
            }
            else
            {
               step--;
            }
         }
      }
   }

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline UprightPath
« Reply #1 - Posted 2012-04-17 21:08:28 »

I had to do this stuff. Well, a Sudoku solver for a class years and years ago.

I'm not looking too closely at your code. I'm assuming that you're doing most things right and just trying to match statement chunks to see if you're obviously missing something. Which you are.

(make this space blank again, and the number available)

I don't see a chunk of code in your thinger that's doing this action. IE- Nothing like this following chunk.
1  
2  
            square[step][level] = BLANK_INT;
            used_nums.remove(i);


Fix that chunk and add it in the appropriate place and you might be closer to your goal. Cheesy

Offline Shane75776
« Reply #2 - Posted 2012-04-17 21:11:53 »

Ah. Yea, thanks for that, but im still pretty sure the rest of my code is way off. :\

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Pages: [1]
  ignore  |  Print  
 
 
You cannot reply to this message, because it is very, very old.

 

Add your game by posting it in the WIP section,
or publish it in Showcase.

The first screenshot will be displayed as a thumbnail.

SHC (22 views)
2014-11-25 12:00:59

SHC (20 views)
2014-11-25 11:53:45

Norakomi (18 views)
2014-11-25 11:26:43

Gibbo3771 (22 views)
2014-11-24 19:59:16

trollwarrior1 (36 views)
2014-11-22 12:13:56

xFryIx (74 views)
2014-11-13 12:34:49

digdugdiggy (52 views)
2014-11-12 21:11:50

digdugdiggy (46 views)
2014-11-12 21:10:15

digdugdiggy (41 views)
2014-11-12 21:09:33

kovacsa (67 views)
2014-11-07 19:57:14
Understanding relations between setOrigin, setScale and setPosition in libGdx
by mbabuskov
2014-10-09 22:35:00

Definite guide to supporting multiple device resolutions on Android (2014)
by mbabuskov
2014-10-02 22:36:02

List of Learning Resources
by Longor1996
2014-08-16 10:40:00

List of Learning Resources
by SilverTiger
2014-08-05 19:33:27

Resources for WIP games
by CogWheelz
2014-08-01 16:20:17

Resources for WIP games
by CogWheelz
2014-08-01 16:19:50

List of Learning Resources
by SilverTiger
2014-07-31 16:29:50

List of Learning Resources
by SilverTiger
2014-07-31 16:26:06
java-gaming.org is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑gaming.org
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!