nice :)

I was able to get N=2000 here (C++), so you don't need to have any constrains ;) This kata is mostly about how much performance you can squeeze before reaching a timeout.

Great Kata. One of the best ones that I have ever solved (C++)

Please, fix for C++:

main.cpp:26:24: warning: comparison of integers of different signs: 'int' and 'std::__cxx11::basic_string<char, std::char_traits, std::allocator >::size_type' (aka 'unsigned long') [-Wsign-compare]
for(int i = 0; i < y.size(); i++){
~ ^ ~~~~~~~~
1 warning generated.

Couple of issues with this:

1. Sorting string before it goes to the algorithm can pass all tests, when it shouldn't.
2. Explanation is a not clear.
3. In C++ instead of string, should be std::string_view 3:-)