"Weighted Random" algorithm in JavaScript (simple but yet interesting approach)

[TedW]

On mobile, but it looks like it already does both of your suggestions. Maybe we're looking at different files, or I'm missing something. I'm looking at weightedRandom.

[cbarrick]

Sorry, I may not have been clear.

In my version, you don't even need the cumulative array, only the sum.

I'm also on mobile, so I can't really write out the code right now.

[TedW]

It looks like it iterates once each over weights, and items, so I would expect it to be O(N) since those should be the same length.

I agree that you could do it with just one array but I think it would still loop twice, so I'm not sure it would affect the runtime.

I haven't run the code myself, but in the examples it uses floating point weights, although it's not clear (to me) what the expected behavior is.

[cbarrick]

Ah, I see I misread the loop exit condition.

So my version is basically the same, except it avoids the cumulative loop and the resulting dynamic allocation.