1|Page
WGU C949 OBJECTIVE ASSESSMENT LATEST
2026/2027 ACTUAL EXAM
Array ......ANSWER......A data structure that stores an ordered list of
items, with each item is directly accessible by a positional index.
Linked List ......ANSWER......A data structure that stores ordered list of
items in nodes, where each node stores data and has a pointer to the
next node.
Bianary Search Tree ......ANSWER......A data structure in which each
node stores data and has up to two children, known as a left child and a
right child.
Hash Table ......ANSWER......A data structure that stores unordered
items by mapping (or hashing) each item to a location in an array (or
vector).
Hashing ......ANSWER......mapping each item to a location in an array (in
a hash table).
Chaining ......ANSWER......handles hash table collisions by using a list for
each bucket, where each list may store multiple items that map to the
same bucket.
pg. 1
,2|Page
Hash key ......ANSWER......value used to map an index
bucket ......ANSWER......each array element in a hash table
ie A 100 elements hash table has 100 buckets
modulo hash function ......ANSWER......computes a bucket index from
the items key.
It will map (num_keys / num_buckets) keys to each bucket.
ie... keys range 0 to 49 will have 5 keys per bucket.
= 5
hash table searching ......ANSWER......Hash tables support fast search,
insert, and remove.
Requires on average O(1)
Linear search requires O(N)
modulo operator % ......ANSWER......common has function uses this.
which computes the integer remainder when dividing two numbers.
Ex: For a 20 element hash table, a hash function of key % 20 will map
keys to bucket indices 0 to 19.
pg. 2
, 3|Page
Max-Heap ......ANSWER......A binary tree that maintains the simple
property that a node's key is greater than or equal to the node's
childrens' keys. (Actually, a max-heap may be any tree, but is commonly
a binary tree).
*a max-heap's root always has the maximum key in the entire tree.
Heap storage ......ANSWER......Heaps are typically stored using arrays.
Given a tree representation of a heap, the heap's array form is
produced by traversing the tree's levels from left to right and top to
bottom. The root node is always the entry at index 0 in the array, the
root's left child is the entry at index 1, the root's right child is the entry
at index 2, and so on.
Max-heap insert ......ANSWER......An insert into a max-heap starts by
inserting the node in the tree's last level, and then swapping the node
with its parent until no max-heap property violation occurs.
The upward movement of a node in a max-heap is sometime called
percolating.
Complexity O(logN)
Max-heap remove ......ANSWER......Always a removal of the root, and is
done by replacing the root with the last level's last node, and swapping
that node with its greatest child until no max-heap property violation
occurs.
Complexity O(logN)
pg. 3
WGU C949 OBJECTIVE ASSESSMENT LATEST
2026/2027 ACTUAL EXAM
Array ......ANSWER......A data structure that stores an ordered list of
items, with each item is directly accessible by a positional index.
Linked List ......ANSWER......A data structure that stores ordered list of
items in nodes, where each node stores data and has a pointer to the
next node.
Bianary Search Tree ......ANSWER......A data structure in which each
node stores data and has up to two children, known as a left child and a
right child.
Hash Table ......ANSWER......A data structure that stores unordered
items by mapping (or hashing) each item to a location in an array (or
vector).
Hashing ......ANSWER......mapping each item to a location in an array (in
a hash table).
Chaining ......ANSWER......handles hash table collisions by using a list for
each bucket, where each list may store multiple items that map to the
same bucket.
pg. 1
,2|Page
Hash key ......ANSWER......value used to map an index
bucket ......ANSWER......each array element in a hash table
ie A 100 elements hash table has 100 buckets
modulo hash function ......ANSWER......computes a bucket index from
the items key.
It will map (num_keys / num_buckets) keys to each bucket.
ie... keys range 0 to 49 will have 5 keys per bucket.
= 5
hash table searching ......ANSWER......Hash tables support fast search,
insert, and remove.
Requires on average O(1)
Linear search requires O(N)
modulo operator % ......ANSWER......common has function uses this.
which computes the integer remainder when dividing two numbers.
Ex: For a 20 element hash table, a hash function of key % 20 will map
keys to bucket indices 0 to 19.
pg. 2
, 3|Page
Max-Heap ......ANSWER......A binary tree that maintains the simple
property that a node's key is greater than or equal to the node's
childrens' keys. (Actually, a max-heap may be any tree, but is commonly
a binary tree).
*a max-heap's root always has the maximum key in the entire tree.
Heap storage ......ANSWER......Heaps are typically stored using arrays.
Given a tree representation of a heap, the heap's array form is
produced by traversing the tree's levels from left to right and top to
bottom. The root node is always the entry at index 0 in the array, the
root's left child is the entry at index 1, the root's right child is the entry
at index 2, and so on.
Max-heap insert ......ANSWER......An insert into a max-heap starts by
inserting the node in the tree's last level, and then swapping the node
with its parent until no max-heap property violation occurs.
The upward movement of a node in a max-heap is sometime called
percolating.
Complexity O(logN)
Max-heap remove ......ANSWER......Always a removal of the root, and is
done by replacing the root with the last level's last node, and swapping
that node with its greatest child until no max-heap property violation
occurs.
Complexity O(logN)
pg. 3
