title: Difference between O(m+n) and O(mn)?
body: <p>I was trying to find the complexities of an algorithm via different approaches. Mathematically I came across one O(m+n) and another O(mn) approach. However I am unable to grasp or say visualize this. It's not like I look at them and get the "Ahh! That's what's going on" feeling! Can someone explain this using their own examples or any other tool?</p>