WGU C949 STUDY GUIDE 2026 || Guaranteed Pass.
Array correct answers A data structure that stores an ordered list of items, with each item is
directly accessible by a positional index.
Linked List correct answers 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 correct answers 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 correct answers A data structure that stores unordered items by mapping (or hashing)
each item to a location in an array (or vector).
Hashing correct answers mapping each item to a location in an array (in a hash table).
Chaining correct answers 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 correct answers value used to map an index
bucket correct answers each array element in a hash table
ie A 100 elements hash table has 100 buckets
modulo hash function correct answers 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 correct answers Hash tables support fast search, insert, and remove.
Requires on average O(1)
Linear search requires O(N)
modulo operator % correct answers 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 correct answers 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 correct answers 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 correct answers 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 correct answers 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)
, Percolating correct answers The upward movement of a node in a max-heap
Min-Heap correct answers Similar to a max-heap, but a node's key is less than or equal to its
children's keys.
Heap - Parent and child indices correct answers Because heaps are not implemented with node
structures and parent/child pointers, traversing from a node to parent or child nodes requires
referring to nodes by index. The table below shows parent and child index formulas for a heap.
ie
1) parent index for node at index 12? 5
*** ((12-1) // 2) = 5 or 12 //2 -1 = 5
2) child indices for a node at index 6? 13 & 14
*** 2 * 6 + 1 = 13 and 2 * 6 + 2 = 14
**Double# and add 1, double# and add 2
Node index Parent Index Child Indices
0 N/A 1, 2
1 0 3, 4
2 0 5, 6
3 1 7, 8
4 1 9, 10
5 2 11, 12
Heap - parent_index correct answers parent_index = (node_index - 1) // 2
or node_index // 2 - 1
Array correct answers A data structure that stores an ordered list of items, with each item is
directly accessible by a positional index.
Linked List correct answers 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 correct answers 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 correct answers A data structure that stores unordered items by mapping (or hashing)
each item to a location in an array (or vector).
Hashing correct answers mapping each item to a location in an array (in a hash table).
Chaining correct answers 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 correct answers value used to map an index
bucket correct answers each array element in a hash table
ie A 100 elements hash table has 100 buckets
modulo hash function correct answers 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 correct answers Hash tables support fast search, insert, and remove.
Requires on average O(1)
Linear search requires O(N)
modulo operator % correct answers 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 correct answers 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 correct answers 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 correct answers 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 correct answers 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)
, Percolating correct answers The upward movement of a node in a max-heap
Min-Heap correct answers Similar to a max-heap, but a node's key is less than or equal to its
children's keys.
Heap - Parent and child indices correct answers Because heaps are not implemented with node
structures and parent/child pointers, traversing from a node to parent or child nodes requires
referring to nodes by index. The table below shows parent and child index formulas for a heap.
ie
1) parent index for node at index 12? 5
*** ((12-1) // 2) = 5 or 12 //2 -1 = 5
2) child indices for a node at index 6? 13 & 14
*** 2 * 6 + 1 = 13 and 2 * 6 + 2 = 14
**Double# and add 1, double# and add 2
Node index Parent Index Child Indices
0 N/A 1, 2
1 0 3, 4
2 0 5, 6
3 1 7, 8
4 1 9, 10
5 2 11, 12
Heap - parent_index correct answers parent_index = (node_index - 1) // 2
or node_index // 2 - 1
