Mike Day wrote: > I confess to finding a slow & exhaustive but correct solution > in PARI-GP, with thanks to John for pointing the package > out to me a while ago. I didn't wait to find an elegant method > in J or otherwise. > > FWIW, I probed the logic of another recent Euler problem > (208) in Dyalog APL, but that didn't provide sufficient precision, > and I had to go to J for the final solution. > > J APL etc are great for exploring these problems. Scaling up > is sometimes a significant extra problem.
I think PARI/GP is one of the best special-purpose tools for some of these problems, especially since you can also compile it and turn it up to eleven. I too had a tough time with #208 in J, although I eventually succeeded. I am not sure what you mean by precision: I was doing it entirely in terms of small integers. I agree with the general point. Project Euler has a number of big depth-first searches which I do not know how to program efficiently in J. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
