1. What is the best-case number of comparisons required to sort a list of n numbers? I am asking here for a specific expression of n, not asymptotic notation. Explain why it is impossible to do any better. What is a known algorithm which can achieve this best case? 2. The final loop in counting sort runs in decreasing order (i.e., it visits the elements of the array from right to left). If it instead ran in increasing order, how would the output differ? 3. Is insertion sort stable? Why or why not? 4. Is heap sort stable? Why or why not?