Question

Suppose we are sorting an array of eight integers using quicksort, and we have just finished the first partitioning with the array looking like this: 2 5 1 7 9 12 11 10, which statement is correct?
a. The pivot could be 7, but it is not 9.
b. The pivot could be 9 but not 7.
c. The pivot could be either 7 or 9.
d. Neither 7 nor 9 is the pivot.

Answer 1

Answer:

c. The pivot could be either 7 or 9.

Explanation:

Since we are trying to sort an array of eight integers using quick sort, from the first partitioning it shows that the pivot or the central point can either be 7 or 9. When you look at the array, it is only 7 and 9 that are placed correctly in the sorted array. Every element to the left of 7 and 9 are smaller and every element on the right of 7 and 9 are integers higher than them. Hence this shows that the pivot lies between 7 or 9.