[Bug libstdc++/81806] Split in pbds works in O(n) instead of O(log n)

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81806

--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Again, GCC's purpose is not to help people in programming contests.