Consider any array representation of an n element binary heap where the elements are stored from index 1 to index n of the array. For the element stored at index i of the array $$\left( {i \le n} \right)$$, the index of the parent is

The number of articulation points of the following graph is

Suppose we want to arrange the n numbers stored in any array such that all negative values occur before all positive ones. Minimum number of exchanges required in the worst case is

Give the correct matching for the following pairs:

Group - 1

(A) $${\rm O}(\log n)$$
(B) $${\rm O}(n)$$
(C) $${\rm O}(n\log n)$$
(D) $${\rm O}({n^2})$$

Group - 2

(P) Selection
(Q) Insertion sort
(R) Binary search
(S) Merge sort