What is faster, nested loops or many loops in sequence?

Question

I have a 2D array of size [3000,3] and I have to find Euclidean Distances between the 3000 values in first dimension 3 times (second dimension). What I am doing now is makin a nested for loop, I looked for ways of making it faster, but the only think I found was setting up a structure as here.

Perhaps doing 3 for loops is faster than doing a nested loop. Does anyone know how the processing time goes in this case?

@roryap stole my question haha. Marcelo, I'd suggest you to try it out yourself. — Camilo Terevinto, Dec 08 '15 at 21:35
See this: http://ericlippert.com/2012/12/17/performance-rant/ — Wai Ha Lee, Dec 08 '15 at 21:35

score 3 · Accepted Answer · edited Dec 08 '15 at 21:41

3

It won't matter at all whether you run a loop three times via nested-loop or via separate loops, as long as the amount of iterations are the same.

If you can improve your algorithm, so that you need fewer iterations (fewer than 3000 x 3), that might get you somewhere.

edited Dec 08 '15 at 21:41

rory.ap

34,009
10
83
174

answered Dec 08 '15 at 21:39

Andreas Vogl

1,776
1
14
18

What is faster, nested loops or many loops in sequence?

1 Answers1