Question 1

If the postorder traversal visits the nodes of a binary tree storing character values in the order of U, G, T, R, A, I, what is the visit order for an inorder traversal of the same binary tree?

Accepted Answer

A)  I, G, U, A, T, R 
B)  R, G, U, I, T, A 
C)  G, U, I, T, A, R 
D)  cannot be determined

Question 2

A completely filled binary tree with a height of 4 has ____ nodes.

Accepted Answer

A)  8 
B)  12 
C)  15 
D)  16

Question 3

What is the complexity of adding an element to a heap?

Accepted Answer

A)  O(1) 
B)  O(log (n)) 
C)  O(n log (n)) 
D)  O(n2)

Question 4

If the postorder traversal of an expression tree is 8, 2, +, 5, /, what is the preorder traversal?

Accepted Answer

A)  +, /, 8, 2, 5 
B)  /, +, 8, 2, 5 
C)  8, +, 2, /, 5 
D)  /, +, 2, 8, 5

Question 5

If the postorder traversal of an expression tree is, 8, 2, +, 5, /, what is the result of an inorder traversal?

Accepted Answer

A)  +, /, 8, 2, 5 
B)  /, +, 8, 2, 5 
C)  8, +, 2, /, 5 
D)  /, +, 2, 8, 5

Question 6

Consider the following tree diagram:  Which of the following statements is NOT correct?

Accepted Answer

A)  N is a descendant of R 
B)  N is a descendant of C 
C)  L is a descendant of C 
D)  H is a descendant of M

Question 7

Consider the following tree diagrams:  Which are binary search trees?

Accepted Answer

A)  I 
B)  II 
C)  I and II 
D)  Neither I nor II

Question 8

You wish to traverse a binary search tree using postorder traversal. Arrange the following actions in the correct order to accomplish this.
I Print the right subtree recursively
II Print the root
III Print the left subtree recursively

Accepted Answer

A)  I, II, III 
B)  III, II, I 
C)  II, III, I 
D)  III, I, II

Question 9

Given the BinarySearchTree class discussed in section 17.3, select a statement to complete the following code segment, so that the resulting binary search tree has a height of 4. BinarySearchTree t = new BinarySearchTree();
t.add("a");
t.add("day");
t.add("in");
__________________
t.add("life");

Accepted Answer

A)  t.add("my"); 
B)  t.add("his"); 
C)  t.add("the"); 
D)  t.add("your");

Question 10

Consider the following tree diagrams:  Which of these trees is considered to be balanced?

Accepted Answer

A)  I 
B)  I and II 
C)  II and III 
D)  I and III

Question 11

Consider the following tree diagram:  Which of the following statements is NOT correct?

Accepted Answer

A)  R is an ancestor of N 
B)  C is an ancestor of N 
C)  D is an ancestor of P 
D)  H is an ancestor of M

Question 12

Which of the following statements about a heap is NOT correct?

Accepted Answer

A)  A heap is a form of binary tree. 
B)  The shape of a heap is very regular. 
C)  A heap is always completely filled at all levels. 
D)  In a heap, both the right and left subtrees of any node store elements that are at least as large as the node value.

Question 13

If a min-heap has 15 nodes, what is known for certain?
I every level of the tree is fully occupied
II at least one level is missing a node
III the root contains the smallest element

Accepted Answer

A)  I 
B)  II 
C)  I and III 
D)  II and III

Question 14

A binary search tree is made up of a collection of nodes organized with smaller data values on the left and greater values on the right relative to any node. Which of the following Node references must be instance variables of any implementation of a Node class?
I root
II left
III right

Accepted Answer

A)  I 
B)  II and III 
C)  I and II 
D)  I, II and III

Question 15

Consider the following binary search tree diagram:  Which nodes will be visited in order to insert the letter E into this tree?

Accepted Answer

A)  H 
B)  H and D 
C)  H, D, and F 
D)  H, D, and A

Question 16

How many times during the heapsort algorithm does the fixHeap method need to be called for a max-heap with n elements?

Accepted Answer

A)  log(n) 
B)  n-1 
C)  n 
D)  n+1

Question 17

Consider the following tree diagrams:  Which of the above are binary search trees?

Accepted Answer

A)  I 
B)  II 
C)  I and II 
D)  Neither I nor II

Question 18

Consider the following tree diagrams:  Which tree represents the arithmetic expression 2 + 5 *4?

Accepted Answer

A)  I 
B)  II 
C)  Both I and II 
D)  Neither I nor II

Question 19

Consider the following Huffman encoding tree:  The letter K will be encoded as ____.

Accepted Answer

A)  10 
B)  010 
C)  001 
D)  100

Question 20

When we map a min-heap with n elements to an array with n + 1 elements, we ignore array element 0, and place the root value at which array index?

Accepted Answer

A)  1 
B)  2 
C)  n 
D)  n+1

Exam 17: Tree Structures

If the postorder traversal visits the nodes of a binary tree storing character values in the order of U, G, T, R, A, I, what is the visit order for an inorder traversal of the same binary tree?

A completely filled binary tree with a height of 4 has ____ nodes.

What is the complexity of adding an element to a heap?

If the postorder traversal of an expression tree is 8, 2, +, 5, /, what is the preorder traversal?

If the postorder traversal of an expression tree is, 8, 2, +, 5, /, what is the result of an inorder traversal?

Consider the following tree diagram: Which of the following statements is NOT correct?

Consider the following tree diagrams: Which are binary search trees?

You wish to traverse a binary search tree using postorder traversal. Arrange the following actions in the correct order to accomplish this. I Print the right subtree recursively II Print the root III Print the left subtree recursively

Consider the following tree diagrams: Which of these trees is considered to be balanced?

Consider the following tree diagram: Which of the following statements is NOT correct?

Which of the following statements about a heap is NOT correct?

If a min-heap has 15 nodes, what is known for certain? I every level of the tree is fully occupied II at least one level is missing a node III the root contains the smallest element

A binary search tree is made up of a collection of nodes organized with smaller data values on the left and greater values on the right relative to any node. Which of the following Node references must be instance variables of any implementation of a Node class? I root II left III right

Consider the following binary search tree diagram: Which nodes will be visited in order to insert the letter E into this tree?

How many times during the heapsort algorithm does the fixHeap method need to be called for a max-heap with n elements?

Consider the following tree diagrams: Which of the above are binary search trees?

Consider the following tree diagrams: Which tree represents the arithmetic expression 2 + 5 *4?

Consider the following Huffman encoding tree: The letter K will be encoded as ____.

When we map a min-heap with n elements to an array with n + 1 elements, we ignore array element 0, and place the root value at which array index?