No, I don't really know why the maths works, but it works!
Here are the notes I made for part two to work this out for a test case before implementing it for the first time to make sure that my method worked.
- Maths with Jay - Chinese remainder theorem
- StackOverflow - Modular multiplicative inverse function in Python
Script output
❯ python .\python\
AoC 2020: day 13 - Shuttle Search
Python 3.8.5
Test cases
1.1 pass
2.1 pass
2.2 pass
2.3 pass
2.4 pass
2.5 pass
2.6 pass
Answers
Part 1: 4782
Part 2: 1118684865113056