Hello. I am not sure how to code the partition around a pivot value pseudocode in the following screenshot for finding the kth smallest value in an array of integers using recursion. I am using C$++.$ Thank you.

There is always a pivot, and because it is not part of either $S_1$ or $S_2,$ the size of the array segment to

be searched decreases by at least $1$ at each step. Thus, you will eventually reach the base case: The

desired value is a pivot. A high$-$level pseudocode solution is as follows.

This pseudocode is not far from a $C++$ function. The only questions that remain are how to

choose the pivot value $p$ and how to partition the array about the chosen $p.$ The choice of $p$ is arbitrary.

Any $p$ in the array will work, although the sequence of choices will affect how soon you reach the

base case. Chapter $11$ gives an algorithm for partitioning the values about $p.$ There you will see how

to turn the function kSma$11$ into a sorting algorithm.