From: "Jan E." <lists@...>
Date: 2012-07-25T10:14:55+09:00
Subject: Re: Help with exercise from Chris Pine's Ruby Book: Sort without using .sort

Hi,

You have to re-initialize new_unsorted with an empty array for every 
iteration. Otherwise it will just keep growing.

It's also important to note that Ruby's variables are *references*. This 
means that variable assignment does *not* copy the value from the right 
variable to the left. Instead, it makes both variables point to the same 
object.

As an example:
a = [1, 2]
b = a  # b points to the same array as a
b.pop  # this also affects a
p a

If you want a copy, you have to actually create it:
b = a.dup  # or a.clone, which is more strict


#--------------
word = [
  'beta',
  'zeta',
  'alpha',
  'depha',
  'cina',
  'emma',
  'bonny',
  'falco'
]

unsorted = word.clone
sorted = []
while unsorted.length > 0
  new_unsorted = []
  smallest = unsorted.pop
  unsorted.each do |testword|
    if testword < smallest
      new_unsorted.push smallest
      smallest = testword
    else
      new_unsorted.push testword
    end
  end
  sorted.push smallest
  unsorted = new_unsorted
end
#--------------


The rest is OK. Of course this algorithm is neither efficient nor 
pretty, but you already said that you just want to get it working.

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