All of Pavgran's Comments + Replies

What's the prime factorisation of 91435293173907507525437560876902107167279548147799415693153?

Good luck. If I understand correctly, that last one's gonna take you at least an hour¹ (or however long it takes to threaten me).

109647247078573083699910710287 × 833904139046784164224502687119

With the right tool, it takes about 12 seconds. 5 to locate the tool, 7 for it to give the answer.

Just nitpicking, of course. You could have easily taken 60-digit primes.

Well, there are programs like Logic Life Search that can solve reasonably small instances of backwards search. This problem is quite hard in general. Part of the reason is that you have to consider sparks in the search. The pattern in question could have evolved from small predecessor pattern, but the reaction could have moved from the starting point and a several dying sparks could have been emitted all around. So you have to somehow figure the exact location, timing and nature of these sparks to successfully evolve the pattern backwards. Otherwise, it qu... (read more)

I've got a very good intuition about foo-vectors from Let's remove Quaternions from every 3D Engine post.