Project Euler Forum

First of all, hi everyone, this is my first message here .

I have an algorithm for this problem, which is fast enough, and I'm getting the same results even after using very big precision, but apparently my answer is wrong. Can someone confirm whether these are correct, or whether they have precision issues? I'm getting some negative results and maybe that's completely wrong...

D(12) = 7576197
D(123) = -1337806
D(1234) = -1505441
D(12345) = 7951919
D(123456) = -3651871
D(1234567) = 8523758

Another related question: would it be possible to get the "One in a hundred" achievement even if my account is private, or only public accounts appear in the top 100?

Thanks.

The most significant 7 digits of D(12) are correct, but D(n) is never negativ!

Only public accounts are counted in the rankings, so you can't get the related awards.

Thank you. I suspected that negative numbers didn't happen, and using small values I've spotted a half-pattern that doesn't seem to hold for my attempts with higher values, which is another hint at the presence of mistakes. The thing is, I've run a few variations on my solution and, although some digits change, the results are mostly the same... so I guess that the mistake is probably on the parts I didn't touch.

Too bad about the private accounts and ranking achievements. Maybe I can still get the "On the Ball" if I'm lucky...