Warm tip: This article is reproduced from stackoverflow.com, please click
big-o complexity-theory math

Is the following big-o notation equivalent to each other?

发布于 2020-04-08 09:29:43

O[ ((1/n)*(log2n)2 + 1/√n) * ( √nlog3(log2n) + √nlog2n ) ] = O [ (log n)3/√n ]

Is the above Big O notation equivalent to each other? I expanded the left side out (not shown here) and it seems that [(log n)3/√n] is the highest power.

If they are equivalent to each other, is there a simpler way of finding out why? Because I think expanding the left side out is too much work.

Questioner
hcoder75
Viewed
73
lenik 2020-02-01 09:32

This: ((1/n)*(log2n)2 + 1/√n) can be replaced with just 1/√n, because the rest is much smaller for large n, while ( √nlog3(log2n) + √nlog2n ) becomes √nlog2n for the same reason, so in the end you have 1/√n * √nlog2n, which is just log2n.