What is the worst-case time complexity of searching for an element in an unbalanced Binary Search Tree containing N nodes?

Options

  • A. O(1)
  • B. O(log N)
  • C. O(N)
  • D. More than one of the above
  • E. None of the above

Correct Answer (Detailed Explanation is Below)

C. O(N)

Detailed Explanation

The worst-case search complexity of a Binary Search Tree is O(N) when the tree becomes completely or nearly skewed. In such a tree, it can behave like a linked list, requiring the search to examine many nodes. A balanced BST has height approximately O(log N), giving logarithmic search. Examples of self-balancing BSTs include AVL trees and Red-Black trees.