For the same code, PyPy performs visibly worse than Python 3. I've heard of i/o operations in PyPy being much slower than in CPython, but why does the memory consumed vary so much too? For the same solution to cf round 869 div 2A, PyPy solution consumes 9500 KB whereas Python 3 solution consumes 0 KB.

PyPy 3-64 submission

Python 3 submission

Can someone explain why this happened?