2d array and ArraySwap

[EvenSteven]

global $array[4][4] = [[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]]

I have a 2d array and using ArraySwap() I wanted to swap through every distinct permutation. Every iteration there's one less possible flip so summation of 0 to 15 = 120 different possibilities. It seems easier to me for a 1d array. So I was thinking maybe it could be possible to call $array[1,0] = 5 as $array[4] for example? Aside from that all I can think of would be convoluted multi variable counting that makes my head hurt just thinking about it.

[PsaltyDS]

First of all, $array[1,0] is bad syntax. Should be $array[1][0].

What does "swap through" mean?

Given your initialized 2D array example, how would it look after it had been "swapped through"?

[EvenSteven]

I wrote a function which does what I want but with a 1d array. Should help to illustrate what I mean. All it does is swap 2 values to get all the different combinations. I think I would break my brain trying to do this with a 2d array. Well it would give several sessions of brain stimulation lol.

#include <array.au3>
global $1d[16] = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

_analyze1d()

func _analyze1d()
        Local $i = 0
        Local $a = 1
        Local $b = 15
        Local $c = 1
    
        While $b > 0
                _ArraySwap($1d[$i], $1d[$i+ $a])
                _arraydisplay($1d)
                _ArraySwap($1d[$i+ $a], $1d[$i])
                $a += 1
                if $a > $b      Then
                        $i += 1
                        $c += 1
                        $b -= 1
                        $a = 1
                EndIf
        WEnd
EndFunc

2d is messing me up because it goes from [0][3] to [1][0] then [1][3] to [2][0]. Though I guess at this point I could just add some if loops and such and manage. It would have been easier if I could use [4] instead of [1][0] for example but whatever. Just writing this down I see a few solutions. but they are going to be pretty convoluted lol.

Edited April 26, 2011 by EvenSteven

[UEZ]

As far as I know the permutation of 16 is 16! = 20922789888000 different possible rearrangements of the elements!

Example:

Permutation of ABC

ABC

ACB

BAC

BCA

CAB

CBA

-> 3! = 6

Are you sure that you want to permute 16 elements?

Br,

UEZ

Edited April 26, 2011 by UEZ

[jchd]

@EvenSteven,

That you arrange values in a 1D, 2D or N-dimentional array is just cosmetic (for your eyes or convenience only). The issue is that permutations get out of reach very fast when the number of elements increases (whatever their arrangement in line, rectangle, square, cube, hypercube or worse), just as UEZ showed you.

[EvenSteven]

I shouldn't have used the word permutation. My bad, that's not what I meant. I switched over to a 1d array anyways and calculated rows and columns elsewhere. Way less complicated than operating on a 2d array. Thanks guys. I wanted to analyze one move at a time and not the complete set actually. So for ABC there would be 3 possibilities. [A to B][A to C][b to C]. But it's all good now. Cheers

Edited April 26, 2011 by EvenSteven

[jchd]

Sounds like what you're dealing with is k-combinations of a n-set, which is described here for instance.