If you are optimizing for LOC, use a suitable language:

from http://nsl.com/papers/qn.htm , the code that computes the solution is

  qn:{[n],/{:[n=#*x;,*x;,/_f'f x,\:/:(!n)_dvl,/x]}'(f:0 -1 1+/:)@!n}

And it uses backtracking, which makes it infinitely faster.

But armin isn't optimizing LOC.