TL 12 107676717 -- unordered_map<int, int> cnt (TL = 2s)
TL 18 107676732 -- unordered_map<int, int> cnt(n) (works 46ms on 12th test)
OK 107676952 -- sort (works 77ms and 66ms on 12th and 18th tests)

What's going on?) I have no access to tests and can not repeat this effect locally (both windows:g++, linux:g++)

UPD:
107679200 rehash(100 + gen() % 10000) gives OK in 670 ms, which is still too slow
107679288 rehash(100 + gen() % 10000) + reserve gives OK in 100 ms, which is strange but acceptable.

PS:
This comment says "anti-hash test". I also have only this idea. Seems developers do not know about universal hashing or can not do "random(time)" by themself to choose hash function, or at least give such an option to users. In future of course i would just use my own hash-table with no such faults.