Data Structures I

Topics:

• Big-O Notation (Complexity analysis)
• Stacks
• Queues
• Linked Lists
• Hash Tables

Stacks

• Should have the methods: push, pop, and a getter for the property size
• push should accept a value and place it on top of the stack.
• pop should remove and return the top value off of the stack.
• size should return how many items are on the stack.

Queues

• Should have the methods: enqueue, dequeue, and a getter for the property size
• enqueue should add an item to the back of the queue.
• dequeue should remove and return an item from the front of the queue.
• size should return the number of items in the queue.

Linked Lists

• Should have the methods: addToTail, removeHead, and contains.
• addToTail replaces the tail with a new value that is passed in.
• removeHead removes and returns the head node.
• contains should searth through the linked list and return true if a matching value is found.
• The head property is a reference to the first node and the tail property is a reference to the last node. These are the only two properties that you need to keep track of an infinite number of nodes. Build your nodes with objects.

Hash Tables

• Should have the methods: insert, remove, and retrieve.
• insert should take a key value pair and add the value to the hash table.
• retrieve should return the value associated with a key.
• remove should removed the given key's value from the hash table.
• Should properly handle collisions. If two keys map to the same index in the storage table then you should store a 2d array as the value. Make each key/value pair its own array that is nested inside of the array stored at that index on the table. (This is often implemented as a linked list but you can just use arrays.)

Extra Credit

• Uncomment the final test in hash-table.test.js and make the hash-table rebalance. As a hash table increases in size the associated storage table will typically double in size once it reaches a certain capacity. Change the hash table so that it doubles the size of the storage table once it is 75% full.
• Re-implement the stack push and pop methods, along with the queue enqueue and dequeue methods, without using built-in array methods.
• Implement a doubly linked list data structure in its own file named doubly-linked-listjs. Uncomment the Extra Credit tests in linked-list.test.js to test your doubly-linked list implementation. Since you've made it this far into the extra credit, you'll be left to read through the tests yourself to figure out what is needed of your implementation for it to pass. Being able to read through documentation and tests in order to glean necessary implementation details is an important skill for any developer.