# Data Structures and Algorithms Multiple Choice Questions - Set 27

261.       The largest element of an array index is called its .................
(A) lower bound.
(B) range.
(C) upper bound.
(D) All of these.
262.       What is the result of the following operation:
Top (Push (S, X))
(A) X
(B) null
(C) S
(D) None of these.
263.       How many nodes in a tree have no ancestors?
(A) 0
(B) 1
(C) 2
(D) n
264.       In order traversal of binary search tree will produce ................
(A) unsorted list
(B) reverse of input
(C) sorted list
(D) none of the above
265.       In binary heap, whenever the root is removed then the rightmost element of last level is replaced by the root. Why?
(A) It is the easiest possible way.
(B) To make sure that it is still complete binary tree.
(C) Because left and right subtree might be missing.
(D) None of these
266.       In order to get the contents of a Binary search tree in ascending order, one has to traverse it in ............
(A) pre-order
(B) in-order
(C) post order
(D) not possible
267.       Which of the following sorting algorithm is stable?
(A) Insertion sort
(B) Bubble sort
(C) Quick sort
(D) Heap sort
268.       The prefix form of an infix expression p + q − r * t is:
(A) + pq − *rt
(B) − +pqr * t
(C) − +pq * rt
(D) − + * pqrt
269.       Which data structure is used for implementing recursion?
(A) Queue
(B) Stack
(C) Arrays
(D) List
270.    In binary search, average number of comparison required for searching an element in a list if n numbers is:
(A) log2 n
(B) n / 2
(C) n
(D) n – 1
1. 