Big-O notation of $n^2/2+n/2$ I'm just starting to use big-O notation and I just wanted to make sure I was on the right track.
My algorithm is the following:
$$\frac12n^2+\frac12n$$
I came up with $O(n^2)$ is that correct?

You are right.
$$O\left({1\over 2} n + {1\over 2} n^2\right)= O\left \{ \max \left({1\over2} n,{1\over2} n^2\right) \right \}=O(n^2)$$
