When are you justified in using an O(n^2) algorithm? (b) Exhaustive search is an example of which type of strategy? Give an example where you might use it (c) What is a Divide-and-Conquer strategy? Give an example. (d) What is a Greedy algorithm? Briefly explain how it works and give an example. (e) A Decrease-by-One strategy is one where the size of the problem to be solved is steadily decreased by one element on each iteration. "Insertion sort is a Decrease-by-One algorithm". Given the definition and your knowledge of insertion sort, is this statement true? Explain your answer and clearly identify the features of insertion sort that are supporting your argument