3. Design a MapReduce algorithm for the following problem: given array A, remove from A all repeats Example: A [1 3 6713 6477]Output: [1 3 674] 4. There is a network that consists of n computers, with some computers having access to other computers. Owner of one of the computers is a hacker. He created a virus, which every day at midnight copies itself to all accessible computers, that have not been infected yet. How to find, after how many days all computers will be infected? How to do it in parallel? Hint: use an algorithm that has been studied in our course