WGU C949 STUDY GUIDE EXAM
LATEST UPDATE 2026
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.
Hash key - answer-value used to map an index
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).
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.
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)
Heap - parent_index - answer-parent_index = (node_index
- 1) // 2
or node_index // 2 - 1
Heap - left_child_index - answer-left_child_index = 2 *
node_index + 1
Heap - right_child_index - answer-right_child_index = 2 *
node_index + 2
LATEST UPDATE 2026
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.
Hash key - answer-value used to map an index
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).
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.
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)
Heap - parent_index - answer-parent_index = (node_index
- 1) // 2
or node_index // 2 - 1
Heap - left_child_index - answer-left_child_index = 2 *
node_index + 1
Heap - right_child_index - answer-right_child_index = 2 *
node_index + 2
