PHP Sudoku

[jagopth]

Hi all,

I was originally going to post this in the Games forum, but this is more of a PHP question, rather than a Flash Games question, therefore I have put it here.

If this is the incorrect forum, please could a mod move it (sorry!)




I have been working on creating a script to randomly generate a full sudoku grid of numbers. This would be sent to flash, with a few numbers hidden, giving the user a unique experience each time they played the game.

My first step, is to create the sudoku grid using PHP, and I've tried various methods, but alas I cant seems to get to a full solution.

Towards the end of the script, it always seems to fail to add between 2-6 numbers based on the fact that the row/column already has the number to add.

On script execution, a random number is chosen, and then checked to ensure that it there is no number that is the same within the same row,column and grid space (there are 9 'grid spaces' within the full sudoku grid)


Ive added my code below. if anyone is willing to suggest any ways that I would be able to get this to work correctly, I would be greatly appreaciative.



Thanks

jagopth


Running the code here =>
http://www.icepets.com/test/sud.php

<?php

$attempt = 0;
while($attempt<3){
    $attempt++;
    $playnum = 0;
    $rownum = 0;
    $colnum = 0;
    $allnums = array();
    print '<br /><br /><table style="margin:auto; width:400px;">';
    while($rownum<9){
        $rownum++;
        $colnum=0;
        print '<tr>';
        while($colnum<9){
            $colnum++;
            $currtry = array();
            print '<td>';
            while(count($currtry)<9){
                $thisnum = rand(1,9);
                if(!in_array($thisnum,$currtry)){
                    //Check Vertical
                    $rowloop = 1;
                    $allowNumber = "yes";
                    while($rowloop<=9){
                        $rowCheck = $allnums[$rownum][$rowloop];
                        if($rowCheck==$thisnum){
                            $allowNumber = "no";
                        }
                        $rowloop++;
                    }
                    //Check Horizontal
                    $colloop = 1;
                    while($colloop<=9){
                        $colCheck = $allnums[$colloop][$colnum];
                        if($colCheck==$thisnum){
                            $allowNumber = "no";
                        }
                        $colloop++;
                    }
                    //Check Grid
                    if($rownum<=3){
                        $baserow = 1;
                    }else if($rownum<=6){
                        $baserow = 4;
                    }else{
                        $baserow = 7;
                    }
                    if($colnum<=3){
                        $basecol = 1;
                    }else if($colnum<=6){
                        $basecol = 4;
                    }else{
                        $basecol = 7;
                    }
                    $full9 = 0;
                    while($full9<9){
                        $full9++;
                        if($full9==4 || $full9==7){
                            $baserow++;
                            $basecol-=3;
                        }
                        $grid_num = $allnums[$baserow][$basecol];
                        if($grid_num==$thisnum){
                            $allowNumber = "no";
                            $full9 = 10;
                        }
                        $basecol++;
                    }
                    
                    if($allowNumber=="no"){
                        array_push($currtry,$thisnum);
                    }else{
                        $allnums[$rownum][$colnum] = $thisnum;
                        array_push($currtry,1,2,3,4,5,6,7,8,9);
                        print $thisnum;
                        $playnum++;
                    }
                }
            }
            print '</td>';
        }
        print '</tr>';
    }
    print '</table>';
    if($playnum==81){
        break;
        print "<br /><br />FULL GRID!";
    }
}
?>