What does Big-O notation represent? How does it relate to program performance?

Most of the run-time for a given program results from an O(n

^{3}) algorithm, where n represents the number of inputs. The program takes 10 seconds to process 1000 inputs. About how long will it take to process 5000 inputs?What is the order of operations for a linear search?

What is the order of operations for a binary search?

What is the order of operations for a matrix addition (n x n matrix).