Let A be a random permutation of [a,b,c,d,e,f,g,h]. Determine the probability that exactly 12 comparisons are required

Show how quicksort can be made to run in O(nlogn) time in the worst case. Assume the input array is A[0:n-1] and all elements in A are distinct. Write your answer as pseudo-code and use plain language to explain the idea of your algorithm. (Hint: you can use any algorithm helper functions in parts of the designed algorithm. If you use an algorithm, you can directly call the function name in the pseudo-code without expanding the details of the helper function, as long as you clearly explain the meaning of the helper function.)

Hi I was wondering if I could get help with this question. I know that the first five  will make the largest sum of 9 but I don't where to go from there  Thanks

Please help (DON'T COPY FROM CHEGG)