From: bei zhao <lists@...>
Date: 2012-06-29T08:02:35+09:00
Subject: stack level too deep for quicksort code

Hi, below is my quicksort implementation in ruby(using the first element
as pivot).

def quicksort(items)
   return items if items.nil? or items.length <= 1

   first=items[0]

   left,right=parti(items,0,items.length)

   quicksort(left) + [first] + quicksort(right)

end

def parti(s,l,r)
  p=s[l]
  i=l+1
  (l+1..r).each do |x|
      if s[x] < p
          s[x],s[i] = s[i],s[x]
          i+=1
      end
  end
  s[l],s[i-1] = s[i-1],s[l]
  return [s[0..i-2],s[i..r]]
end

But it shows stack level too deep error.
I tried to add puts after
left,right=parti(items,0,items.length)
and see iterate outputs.

Any thoughts?

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