I don't get this post. O notation specifies the asymptotic behavior of (mathematical) functions. e.g. sqrt(n) = O(n/log(n)) In order to use O notation to desc

I don't get this post. O notation specifies the asymptotic behavior of (mathematical) functions. e.g. sqrt(n) = O(n/log(n)) In order to use O notation to describe the performance of an algorithm, one must specify 1. What is being measured and 2. What is the class of inputs.