What's the deal with 998244353?

Revision en1, by usernameson, 2018-10-18 08:21:24

I have noticed that educational rounds like to use mod 998244353 instead of mod 109 + 7. Does anyone know the reason for this? One idea that comes to mind is since 998244353 < 109 there might be opportunities to troll contestants by breaking division and forcing them to calculate things like mod 998244353. However I have yet to see this used in an educational round, although this idea was used to good effect in 272D - Дима и две последовательности.

Tags #number theory, educational round

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en1 English usernameson 2018-10-18 08:21:24 505 Initial revision (published)