Need An Algorithm

[Wynder]

I'm being a bit lazy here -- normally I'd find a big whiteboard and work this out, but if someone has something similar off hand, might as well try here first. 🙂 Here's the table layout.

form_id, form_name, order

So, you have 30 or 40 different forms that are ordered by order. I want to, for instance, move the third form to the 10th form. So, assuming I read the table into an array, does anyone know the flow of how the renumbering would go? 🙂

[bubblenut]

Depends how you want to do it.
Do you want to plain swap them?
Do you want to shift the positions of 4-10 down one?

[Wynder]

Good point.. since this is going to be done in the web, I'll prolly have a listbox (dropdown with a size attribute), I'll prolly do it one at a time.

User can highlight a form and click an UP or a DOWN button. So, three would move down to four, four up to three. Might actually be able to throw this stuff into something like a queue or a stack.

Another thing.. forms can also be deleted. But another field (deleted) is set to Y instead of N... so if you have a deleted form still in the order say, 8, 9, 10 and 9 is 'deleted', if you try to shift 8 to 10, it has to get around 9 somehow. Heh.

What a mess. 🙂 Where's that whiteboard.

[bubblenut]

Probably easier to implement as an array ques and stacks are not really designed for elements over taking each other.

<?php
function moveUp($i, &$array) {
  $temp=$array[$i];
  $array[$i]=$array[$i+1];
  $array[$i+1]=$temp;
}

function moveDown($i, &$array) {
  $temp=$array[$i];
  $array[$i]=$array[$i-1];
  $array[$i-1]=$temp;
}

function delete($i, &$array) {
  for($x=$i;$x<(count($array)-1);$x++) {
    $array[$x]=$array[$x+1];
  }
  unset($array[$x]);
}
?>

HTH
Bubble