OpenEuphoria

Re: Simple program needed (help)

• Posted by Ricardo M. Forno <rmforno at tutopia.com> Mar 07, 2006
• 397 views

faz wrote:
> 
> Hi
> 
> I hope someone can help me out with a very SIMPLE program 
> about whole string permutations. That is: given a list of strings, 
> the required outcome is a complete set of all their possible permutations.
> It's like character permutations of a string, but this time it is 
> whole strings instead of single characters that have to be permuted.
> 
> I need this because I don't remember exactly the password to open 
> my zipped archives, but i do remember the bits of strings 
> that made up the long passphrase.
> 
> Could someone kindly write a simple program that, after reading a set of 
> strings contained in a .txt file (one string on each line), 
> produces as output another .txt file containing all the possible 
> permutations/combinations of those strings.
> 
> For example, the text file with the set of strings may contain:
> 
> HOUSE
> jolly
> ---
> 0&
> 99
> 
> 
> and the output file contains:
> 
> HOUSE
> HOUSEjolly
> HOUSE---
> HOUSE0&
> 
> and so on...
> ...with the word combinations growing extensively,
> so as to exhaust all the possibilities:
> 
> e.g. 
> 
> ---99jolly0&
> jolly0&---99HOUSE
> 
> etc. etc.
> 
> Unfortunately I am not able to program it myself, so 
> I would appreciate if someone could write this piece of 
> software, compile it (for DOS or Windows) and send it to:
> 
> lory88 at gmail . com
> 
> 
> I thank you all in advance.
> 
> Lory
Hi, Lory.
At this time I cannot completely answer your request, but I think the following
code, that you can also find in my General Funtons package, will help you to get
your job done.

--/topic STATISTICS / PROBABILITIES ROUTINES
--/func Permutation(sequence set, integer size, integer which)
--/desc Obtains a permutation of the elements of a set
--/ret A sequence containing a specified permutation of the argument sequence
--Returns a sequence containing the permutation with size 'size',
-- numbered 'which', from the set 'set'.
--The set is any sequence of objects, and so is the result.
--'which' starts at 1 and goes to the number of existing permutations
-- of this size.
--If 'which' is out of bounds, an atom containing -1 is returned.
--Thanks to Henri Goffin for a correction.
--Example: Permutation("ABCDE", 3, 4) gives "ACB"
global function Permutation(sequence set, integer size, integer which)
    integer c, len, a
    len = length(set)
    if size <= 0 then
	return - 1
    elsif size = 1 then
	if which <= len then
	    return {set[which]}
	else
	    return - 1
	end if
    end if
    c = 1
    for i = len - size + 1 to len - 1 do
	c *= i
    end for
    a = floor((which - 1) / c)
    which -= a * c
    a += 1
    if a > len or a <= 0 then
	return - 1
    end if
    return {set[a]} & Permutation(set[1..a-1] & set[a+1..len], size - 1, which)
end function

You should call it with increasing values for 'which', starting at 1.

Regards