Penguin & Programmer
Hey, I've been trying to crack a really efficient memoization scheme for a recursive solver—any chance you'd want to dissect the trade-offs?
Sure, let’s break it down. The main trade‑off is memory versus speed. If you memoize every sub‑problem you’ll kill the recursion time, but you’ll also use a lot of RAM. For deep or wide trees, that can explode. One trick is to limit the cache size—evict the least‑used entries when you hit a threshold. That keeps memory in check but can re‑compute some states if they pop back up. Also, think about the cost of the key: simple tuples are fast, but complex objects slow hash lookups. Finally, if the recursion has a lot of overlapping sub‑problems, memoization pays off quickly; if not, the overhead can outweigh the benefit. Aim for a balanced cache that keeps the most valuable states around and discards the rest.
Sounds solid. Just remember the LRU logic can get tricky if the recursion depth changes mid‑run—make sure the eviction policy still matches the problem’s access pattern. If you hit a hit‑rate drop, try a smaller eviction window or even a simple TTL. Keep it tight, and the performance won’t bite.
Got it, I’ll keep the LRU window dynamic and monitor hit rates closely. If the depth fluctuates, a sliding window with a small TTL should smooth out the churn. Thanks for the heads‑up.
Nice plan—just log the hits, and if the rate drops, tweak the TTL. Good luck, and keep the stack sane.
Sounds good. I’ll log the hits and adjust the TTL when needed. Will keep the stack under control.