Re^3: Iterating through Two Arrays. Is there a better use of memory?

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Re^4: Iterating through Two Arrays. Is there a better use of memory? by AR (Friar) on Oct 13, 2011 at 17:17 UTC
Almost definitely. The worst case scenario with hashes is if every hashed key collides. In that case, you may as well be using an array.	[reply]
Re^4: Iterating through Two Arrays. Is there a better use of memory? by DentArthurDent (Monk) on Oct 13, 2011 at 17:21 UTC
That's exactly what I'm saying. Your first algorithm has quadratic growth (not exponential). The second algorithm has linear growth. It's a linear cost in the smaller array to load up the hash and then a linear cost in the larger array to do all the look-ups. By the way: exponential growth would be O(n^m). Your original algorithm is polynomial, or quadratic to be precise O(n^2). Ben ---- My mission: To boldy split infinitives that have never been split before!	[reply]
Re^5: Iterating through Two Arrays. Is there a better use of memory? by JavaFan (Canon) on Oct 13, 2011 at 20:34 UTC
Note that it's only the runtime that's quadratic (or, to be precise, `O(n*m)`). The memory usage of the algorithm is bounded by `O(n+m)`.	[reply] [d/l] [select]