WGU C949 DATA STRUCTURES AND
ALGORITHMS STUDY GUIDE 2026
COMPREHENSIVE Q&A PASSED
⩥ Array. Answer: Data structure that stores an ordered list of items, w/
each item directly accessible by a positional index.
⩥ Linked List. Answer: Data structure that stores an ordered list as
nodes, each node stores data and has a pointer to the next node.
⩥ Binary Tree. Answer: Data structure where each node stores data and
has up to two children, left child and right child.
⩥ Hash Table. Answer: Data structure that stores unordered items by
mapping each item to a location in an array.
⩥ Max Heap. Answer: Tree that maintains the simple property that a
node's key is greater than or equal to a node's children key.
⩥ Min Heap. Answer: A tree that maintains simple property that node's
key is less than or equal to the node's children key.
, ⩥ Graph. Answer: Represents connections among items. Consists of
vertices and edges. Vertex represents an item on a graph. Edges
represent a connection between two vertices.
⩥ Abstract Data Type (ADT). Answer: Data type described by
predefined user operations. Does not say anything about the
implementation.
⩥ List. Answer: Common ADT for holding ordered data.Like an array.
Can store ints, strings.
Ex. nums = [5, 25, 30]
⩥ Queue. Answer: ADT where items are inserted at the end of the queue
and removed at the front of the queue. First in first out ADT.
push - inserts items at the end of the queue
pop - removes and returns the item at the front of the queue.
⩥ Dictionary. Answer: Maps keys to values. Uses {}. The value can be
number,string, or tuple. Can be any type.
ex. players = {
'Lionel Messi': 10,
'Christiano Ronaldo': 7
}
ALGORITHMS STUDY GUIDE 2026
COMPREHENSIVE Q&A PASSED
⩥ Array. Answer: Data structure that stores an ordered list of items, w/
each item directly accessible by a positional index.
⩥ Linked List. Answer: Data structure that stores an ordered list as
nodes, each node stores data and has a pointer to the next node.
⩥ Binary Tree. Answer: Data structure where each node stores data and
has up to two children, left child and right child.
⩥ Hash Table. Answer: Data structure that stores unordered items by
mapping each item to a location in an array.
⩥ Max Heap. Answer: Tree that maintains the simple property that a
node's key is greater than or equal to a node's children key.
⩥ Min Heap. Answer: A tree that maintains simple property that node's
key is less than or equal to the node's children key.
, ⩥ Graph. Answer: Represents connections among items. Consists of
vertices and edges. Vertex represents an item on a graph. Edges
represent a connection between two vertices.
⩥ Abstract Data Type (ADT). Answer: Data type described by
predefined user operations. Does not say anything about the
implementation.
⩥ List. Answer: Common ADT for holding ordered data.Like an array.
Can store ints, strings.
Ex. nums = [5, 25, 30]
⩥ Queue. Answer: ADT where items are inserted at the end of the queue
and removed at the front of the queue. First in first out ADT.
push - inserts items at the end of the queue
pop - removes and returns the item at the front of the queue.
⩥ Dictionary. Answer: Maps keys to values. Uses {}. The value can be
number,string, or tuple. Can be any type.
ex. players = {
'Lionel Messi': 10,
'Christiano Ronaldo': 7
}
