Big-O Notation

O(N) O(N^2)

O(logN)

O(NlogN) vs. O(logN)

https://www.quora.com/How-can-we-check-for-the-complexity-log-n-and-n-log-n-for-an-algorithm

O(logN) - A set of data recursively divided into half, and the middle element is processed. eg. Binary Search Algorithm

O(NlogN) - A set of data recursively divided into half, and each half is processed individually again. eg. Merge sort Algorithm, heap sort, quick sort