Which node is the inorder predecessor of a BST node X when X has a non-empty left subtree?
If X has a non-empty left subtree, move to X's left child and then follow right-child links until reaching the maximum key; that node is the inorder predecessor.
What is a Degenerate (or Skewed) Binary Tree?
A skewed binary tree has all nodes dominated by left or right children, degrading tree performance down to O(n) linear linked list behavior.
Which statement gives the exact worst-case time complexity of extracting the maximum element from a binary Max Heap with n elements?
Extract-Max removes the root and restores heap order by heapify-down, taking Θ(log n) worst-case time. None of A-C is Θ(log n).
How many total null pointers are replaced with threads in a Fully Threaded Binary Tree of n nodes?
Since a binary tree of n nodes has n + 1 NULL pointers, a fully threaded binary tree utilizes all n + 1 pointers as threads (except extreme ends pointing to dummy head).
Which tree balancing technique uses color attributes ('Red' and 'Black') on nodes to enforce logarithmic balance?
Red-Black Trees store a 1-bit color flag per node and enforce color invariants to ensure tree height remains O(log n) during insertions/deletions.