Draw the recursion tree of this algorithm

Quicksort can be modified to obtain an elegant and efficient linear (O(n)) algorithm QuickSelect for the selection problem. Quick select (A, p, r, k) {p & r-starting and ending indexes; to find k-th smallest number in non-empty array A; 1 lessthanorequalto k lessthanorequalto (r - p + 1)} if p = r then return A[p] else q = Partition (A, p, r) pivot Distance = q - p + 1 if k = pivot Distance then return A[q] else if k