From: Joshua Muheim <forum@...>
Date: 2009-10-01T04:47:28+09:00
Subject: SystemStackError: stack level too deep > how make it deeper?

Hi all

I have a recursive algorith that must run until it finds the result:

def p(n)
  n * (3 * n - 1) / 2
end

def h(n)
  n * (2 * n - 1)
end

def find_next_match(p, h)
  result_p = p(p + 1)
  result_h = h(h + 1)
  if result_p == result_h # Resultat gefunden!
    return result_p
  else
    result_p < result_h ? p += 1 : h += 1

    puts "find next match for p=#{p} (#{result_p}) and h=#{h}
(#{result_h})"
    find_next_match(p, h)
  end
end

The task is to find the next pair of p and h that result in the same
number. The first pair is 165 and 143, so I run it with these arguments:

puts find_next_match(165, 143)

Sadly, after some seconds, Ruby throwns a SystemStackError:

SystemStackError: stack level too deep
method p  in uebung-2-1.rb at line 2
method find_next_match  in uebung-2-1.rb at line 10
method find_next_match  in uebung-2-1.rb at line 18
at top level  in uebung-2-1.rb at line 22
copy output
Program exited with code #1 after 8.29 seconds.

But I'd like to run it and run it and run it without this limitation. Is
there a workaround for this, so I can change the stack level maximum?

Thanks a lot for help
Josh
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