Help - just a few lines of code needed

Ruby
1

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 the .exe file to:

lory88 at gmail . com

I thank you all in advance.

Lory

2

On Mar 7, 2006, at 2:23 AM, [email protected] wrote:

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.

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 the .exe file to:

Follow the Python folks’ suggestion[1], but go to ruby-lang.org
instead. :wink:

[1] http://mail.python.org/pipermail/python-list/2006-March/329541.html

3

William J. wrote:

the_list = gets(nil).split

If your strings can contain spaces, change to

the_list = gets(nil).split(/\n+/)

4

[email protected] wrote:

my zipped archives, but i do remember the bits of strings
HOUSE
HOUSE—

Lory

=begin
A problem in combinations and permutations.
Let’s lift some code from this newsgroup.
=end

class Array
def permute(prefixed=[])
if (length < 2)
yield(prefixed + self)
else
each_with_index { |e, i|
(self[0,i]+self[(i+1)…-1]).permute(prefixed+[e]) {|a|
yield a }
}
end
end
end
module Combine
def Combine.pick(pick, items, &block)
combine([], 0, pick, items, &block)
end

private

def Combine.combine(set, index, pick, items, &block)
if pick == 0 or index == items.length
yield set
else
set.push(items[index])
combine(set, index + 1, pick - 1, items, &block)
set.pop
combine(set, index + 1, pick, items, &block) if
pick < items.length - index
end
end
end

You’re right. We only have to write a few lines of code.

the_list = gets(nil).split

1.upto(the_list.size) {|n|
Combine.pick( n, the_list ) {|ary|
ary.permute {|ary_p| puts ary_p.join }
}
}