During this CTF challenge, we have a file with 1M large numbers and we have to find the pairs where y + z equals a known x. This is very slow if you write to loops but you can speed it up using some maths and then some CPython capabilities.
I'll talk about Data Structures and the fundamental difference between Lists and Sets and then we will have a short look at the CPython source code to understand this Hash Table thing even further.
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https://www.youtube.com/watch?v=qgLssa76i8k