Re^4: Iterating through Two Arrays. Is there a better use of memory?

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

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My mission: To boldy split infinitives that have never been split before!

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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]