Hello y'all! I'm new to Codeforces and I am trying to solve this 1974F

Here is my submission. My approach is to sort the points by the x- and y-axes and use a two pointers approach that slowly closes in on the grid to find the answer. My analysis says my solution should run in O(nlogn + n + m) time, but it appears to TLE on test 7 and takes quite a while for smaller inputs.

Is cache efficiency the reason here? My algorithm is pretty cache inefficient, but cache efficiency feels more like a constant-time optimization that wouldn't really impact an algorithm that TLEs. What are your thoughts on this?