I saw editorial of first problem of JULY LONG DIV1 (missing a point) and there is a section which says :-
We could think that simply changing the data structure to a hash-based one with O(1)O(1) queries/updates (like
unordered_map in C++ or
HashMap in Java) should work, yes it may do trick and our complexity would be O(N)O(N), however I was evil and included some antihash tests.
Can someone tell me what antihash test is ?
PS: I also google about it but didn’t understand.