Math/Statistics Problem - Possible Combinations of Number Sequance - Need Help

[siteturbo]

Hello All:

 

I've been trying this for the last 3 or 4 days and haven't figured it out yet.  Any help would be appreciated.

 

THE PROBLEM:

 

I am trying to output a sequence or combination numbers, from say, 1 through 5 using only the digits 1 through 5, and all their possible combinations.

Example #1:

 

digits 1, 2, 3

 

The possible combinations are...

 

1,2,3

1,3,2

2,1,3

2,3,1

3,2,1

3,1,2

 

Example #2:

 

digits 1, 2, 3, 4

 

The possible combinations are...

 

1,2,3,4

1,2,4,3

1,3,2,4

1,3,4,2

1,4,2,3

1,4,3,2

2,1,3,4

2,1,4,3

and so on...

 

HINT...

 

I know that each solution should have n! (n factorial) solutions.  In other words, for 3 digits (numbers 1 through 2), there are 3! solutions, or 3x2x1 = 6 solutions.  For 4 digits, there are 4! solutions, or 4x3x2x1 = 24 solutions.  And so on.

 

I would like to be able to plug in a number, say "X", and get all combinations of all numbers form 1 to "X".

 

I've tried nesting for loops, trying using one for loop with multiple expressions, etc.  However, no success.

 

Anyone with a lot of brain power want to give it a shot?!

 

Thanks a bunch!

 

--

Ed

[MatthewJ]

Sounds like homework

[siteturbo]

Yeah, I almost had it a couple of times, but have not triumphed yet.  It's become a puzzle to me.   

[siteturbo]

I found the exact solution to my problem at http://cogo.wordpress.com/2008/01/08/string-permutation-in-php/

[GrooN]

You know theres a formula for this right?

 

a b c d

 

how many different ways can that be show:

 

1 * 2 * 3 * 4 = 24

 

24 possible ways to display that.

[akitchin]

groon, you didn't at all help - if you read his original post, he points out that he already knows how many permutations can exist for the given series (n!).

 

siteturbo, if this thread is solved, please mark it as such.

[GrooN]

Yea, okay sorry. My bad... ^^