unordered_map hashing function

Revision en1, by jerdno, 2020-06-28 20:32:02


I'm trying to move from using Java for CP to C++. As such I'm missing some knowledge, but usually I'm able to google it. Today I encountered something that doesn't make sense for me and wasn't able to find good answer for that. In this solution for latest Div 3 contest (problem D) I used unordered_map and received TLE. Then I changed it to map and got Accepted.

I know that what are the differences between map and unordered_map, but I would expect unordered_map to be even faster then map. Does hashing ints really creates so many conflicts, or I'm missing something (for example initialization of size of hash table)?



  Rev. Lang. By When Δ Comment
en1 English jerdno 2020-06-28 20:32:02 791 Initial revision (published)