From: Josh Cheek <josh.cheek@...>
Date: 2009-08-08T19:39:35+09:00
Subject: Re: what is "stack level too deep (SystemStackError)" error

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On Fri, Aug 7, 2009 at 6:52 PM, Mrmaster Mrmaster <mrsolarlife@gmail.com>wrote:

> Hi,
>
> I've created a binary search using code from wiki and when i run it i
> get there error stated below. I'm only using 10 entries so i'm not sure
> why it would give me that error. How can I modify my code to handle 100k
> entries?
>
> test.rb:14:in `binSearch': stack level too deep (SystemStackError)
>  from test.rb:14:in `binSearch'
>  from test.rb:20
>
>
>
>
>
> Here is my code:
>
> array = [1, 2, 3, 4, 5, 6, 7, 8, 9 , 10 , 11, 12, 13, 14, 15]
> target = 6
> left = 0
> right = (array.length)
>
>
> def binSearch(left, right, target, array)
>  middle = left + ((right - left) / 2)
>  if array[middle] == target then
>    puts target
>  elsif array[middle] > target then
>    return binSearch(left, middle, target, array)
>  elsif array[middle] < target then
>    return binSearch(middle, right, target, array)
>  else
>    puts "Target does not exist"
>  end
> end
>
> binSearch(left, right, target, array)
> --
> Posted via http://www.ruby-forum.com/.
>
>
Hi, you have two issues with your algorithm, that I see. Here is what I
would do http://pastie.org/576485 it explains what the two issues are, shows
how I would change the code to fix them, as well as a few other small
changes to make the code more usable, then runs through a few tests to make
sure that it is doing what we think it is doing.

In some browsers, pastie seems to word wrap, so if it does that for you, you
should probably c&p it into your text editor for reading.

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