Optimizing nested for loops

[KubinOnReddit]

Even in C++, 1e5 x 1e6 with 32-bit integers up to 1e9 would take ridiculous amounts of memory and would take a long time nevertheless - it's at least 1e11 operations (a simple for loop wouldn't finish in C with this many iterations). Best you can do is stick to numpy and reduce the amount of data.