Problem E is very similar to this on GFG: https://www.geeksforgeeks.org/find-two-numbers-sum-xor.

They are almost identical (you only need a small observation to notice they basically ask the same thing).

And when plagiarism checking begins, lots of people (including me) shouldn't get plagged bcz the authors created a VERY similar problem, that already exists.

First submission with Cin/Cout w/o Sync: 185094688, 3915 ms

Second one with Scanf/Printf: 185094426, 1357 ms

Shouldn't that be exactly the opposite ?

Because almost everywhere its mentioned that Cin/Cout w/o Sync should be faster, or at least same speed as Scanf/Printf.

Why is it so ?

Everyone says it's 10^9 operations, but that's way too slow.