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Doubt in Modular Arithmetic

Revision en1, by bugdone, 2021-08-09 22:19:43

Today in 1557C - Moamen and XOR I wanted to compute $$${(2^{k-1})}^{n}$$$. But instead of writing binpow(binpow(2, k — 1), n), I simplified it to $$$2^{n*(k-1)}$$$ and wrote binpow(2, mul(n, k — 1)) and failed to pass pretest 2.

Why are not the two equivalent?

Tags #modular arithmetic, #help

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  Rev. Lang. By When Δ Comment
en2 English bugdone 2021-08-09 22:23:40 10
en1 English bugdone 2021-08-09 22:19:43 355 Initial revision (published)