WGU C949 V5 DATA STRUCTURES AND
ALGORITHIMS |ACTUAL QUESTIONS
AND 100% CORRECT VERIFFIED
ANSWERS |2026/2027 COMPLETE
STUDY GUIDE EXAM PREP PRACTICE
WGU C949 Course Coverage Summary
C949 – Data Structures and Algorithms I is a 4-credit course covering dynamic data structures and
associated algorithms using Python . The Objective Assessment contains questions and covers three
competency areas :
Competency Area Weight
Data Types 36%
Data Structures 30%
Algorithms 34%
pg. 1 SUCCESS!!!
,Key topics include: Abstract Data Types (ADTs), Big-O complexity, Arrays, Linked Lists, Stacks, Queues,
Deques, Hash Tables, Binary Search Trees, Heaps, Tree Traversals, Searching Algorithms, Sorting Algorithms,
and Recursion .
Representative Practice Questions with Rationales
Data Types and Big-O (Competency 1)
1. What is the runtime complexity of the expression 305 + O(325*N)?
A) O(N²)
B) O(N³)
C) O(N^N)
D) O(N)
Answer: D) O(N)
Constants are dropped in Big-O notation. The term O(325N) dominates, and since 325 is a constant, it
simplifies to O(N). The constant 305 is negligible in asymptotic analysis* .
2. What is the runtime complexity of three nested loops, each iterating N times?
A) O(3)
B) O(N²)
C) O(N)
D) O(N³)
Answer: D) O(N³)
Three nested loops each iterating N times results in N×N×N executions of the innermost statement, which is
O(N³) .
3. Which data type should be used for the variable phoneNum = "212-555-1212"?
A) Long
B) Short
C) String
D) Integer
Answer: C) String
The value is a sequence of characters including digits and hyphens, which is a string (text) data type, not a
numeric type .
pg. 2 SUCCESS!!!
,4. What is a characteristic of keys in an associative dictionary data type?
A) They are unique and mutable.
B) They are unique and immutable.
C) They are non-unique and mutable.
D) They are non-unique and immutable.
Answer: B) They are unique and immutable.
Dictionary keys must be unique (no duplicates) and immutable (cannot be changed after creation). Values,
however, can be mutable .
5. Which category of data does ("FB", 75.00, 75.03, 74.90) represent?
A) List
B) Tuple
C) Dictionary
D) Array
Answer: B) Tuple
A tuple is an immutable, ordered container. The parentheses and comma-separated values indicate a tuple
containing a string and three floats .
Data Structures (Competency 2)
6. Which abstract data type (ADT) is characterized by the LIFO (Last-In, First-Out) principle?
A) Queue
B) Stack
C) List
D) Dictionary
Answer: B) Stack
A stack is defined by LIFO behavior—the last element added is the first removed, like a stack of plates. A
queue is FIFO (First-In, First-Out) .
7. Which queue operation removes an item from the front of the queue?
A) Enqueue
B) Dequeue
pg. 3 SUCCESS!!!
, C) Pop()
D) Append()
Answer: B) Dequeue
In a FIFO queue, dequeue removes the element at the front (the one that has been waiting longest). Enqueue
adds to the rear .
8. Which function in Python is used to find a specific value in a tuple?
A) count()
B) find()
C) search()
D) index()
Answer: D) index()
The index() method searches a tuple and returns the position of the first occurrence of a specified value.
count() returns the number of occurrences, not the position .
9. Inserting an item at the beginning of a 999-item array requires how many items to be shifted?
A) 0
B) 1
C) 500
D) 999
Answer: D) 999
Inserting at the beginning requires shifting every existing element one position to the right to make room. This
is why array insertion at the front is O(N) .
10. Inserting an item at the end of a 999-item linked list requires how many items to be shifted?
A) 0
B) 1
C) 500
D) 999
Answer: A) 0
A linked list simply adds a new node at the end by updating the tail's pointer. No existing elements need to be
shifted, unlike with an array .
11. What is the primary advantage of a hash table?
pg. 4 SUCCESS!!!
ALGORITHIMS |ACTUAL QUESTIONS
AND 100% CORRECT VERIFFIED
ANSWERS |2026/2027 COMPLETE
STUDY GUIDE EXAM PREP PRACTICE
WGU C949 Course Coverage Summary
C949 – Data Structures and Algorithms I is a 4-credit course covering dynamic data structures and
associated algorithms using Python . The Objective Assessment contains questions and covers three
competency areas :
Competency Area Weight
Data Types 36%
Data Structures 30%
Algorithms 34%
pg. 1 SUCCESS!!!
,Key topics include: Abstract Data Types (ADTs), Big-O complexity, Arrays, Linked Lists, Stacks, Queues,
Deques, Hash Tables, Binary Search Trees, Heaps, Tree Traversals, Searching Algorithms, Sorting Algorithms,
and Recursion .
Representative Practice Questions with Rationales
Data Types and Big-O (Competency 1)
1. What is the runtime complexity of the expression 305 + O(325*N)?
A) O(N²)
B) O(N³)
C) O(N^N)
D) O(N)
Answer: D) O(N)
Constants are dropped in Big-O notation. The term O(325N) dominates, and since 325 is a constant, it
simplifies to O(N). The constant 305 is negligible in asymptotic analysis* .
2. What is the runtime complexity of three nested loops, each iterating N times?
A) O(3)
B) O(N²)
C) O(N)
D) O(N³)
Answer: D) O(N³)
Three nested loops each iterating N times results in N×N×N executions of the innermost statement, which is
O(N³) .
3. Which data type should be used for the variable phoneNum = "212-555-1212"?
A) Long
B) Short
C) String
D) Integer
Answer: C) String
The value is a sequence of characters including digits and hyphens, which is a string (text) data type, not a
numeric type .
pg. 2 SUCCESS!!!
,4. What is a characteristic of keys in an associative dictionary data type?
A) They are unique and mutable.
B) They are unique and immutable.
C) They are non-unique and mutable.
D) They are non-unique and immutable.
Answer: B) They are unique and immutable.
Dictionary keys must be unique (no duplicates) and immutable (cannot be changed after creation). Values,
however, can be mutable .
5. Which category of data does ("FB", 75.00, 75.03, 74.90) represent?
A) List
B) Tuple
C) Dictionary
D) Array
Answer: B) Tuple
A tuple is an immutable, ordered container. The parentheses and comma-separated values indicate a tuple
containing a string and three floats .
Data Structures (Competency 2)
6. Which abstract data type (ADT) is characterized by the LIFO (Last-In, First-Out) principle?
A) Queue
B) Stack
C) List
D) Dictionary
Answer: B) Stack
A stack is defined by LIFO behavior—the last element added is the first removed, like a stack of plates. A
queue is FIFO (First-In, First-Out) .
7. Which queue operation removes an item from the front of the queue?
A) Enqueue
B) Dequeue
pg. 3 SUCCESS!!!
, C) Pop()
D) Append()
Answer: B) Dequeue
In a FIFO queue, dequeue removes the element at the front (the one that has been waiting longest). Enqueue
adds to the rear .
8. Which function in Python is used to find a specific value in a tuple?
A) count()
B) find()
C) search()
D) index()
Answer: D) index()
The index() method searches a tuple and returns the position of the first occurrence of a specified value.
count() returns the number of occurrences, not the position .
9. Inserting an item at the beginning of a 999-item array requires how many items to be shifted?
A) 0
B) 1
C) 500
D) 999
Answer: D) 999
Inserting at the beginning requires shifting every existing element one position to the right to make room. This
is why array insertion at the front is O(N) .
10. Inserting an item at the end of a 999-item linked list requires how many items to be shifted?
A) 0
B) 1
C) 500
D) 999
Answer: A) 0
A linked list simply adds a new node at the end by updating the tail's pointer. No existing elements need to be
shifted, unlike with an array .
11. What is the primary advantage of a hash table?
pg. 4 SUCCESS!!!
