They both have

This is hard version of the problem, it differs from the easy one only by constraints on $$$n$$$ and $$$k$$$.

But there's actually another difference which is the memory limit.

I submitted my G2 AC solution to G1 and got MLE when I was taking VP today. I admit that this was because I was careless and I didn't read the limits of the two problems carefully. But I also saw the "only" in the sentence so I didn't check that. Should this difference be written into it?