This is a repository of implementations for whiteboard questions that I've gotten during interviews.

So far, the goal is to account for the following interview questions:

• Shortest path on an undirected graph. - COMPLETE
• HashMap implementation. - COMPLETE
• Linked hash map (hash table that allows iteration over its keys in the order in which they were inserted). - COMPLETE
• Cartesian product of strings. - COMPLETE
• Postfix to infix arithmetic conversion. - COMPLETE
• Merge two sorted arrays of integers. - COMPLETE
• Reversal of a linked list. - COMPLETE
• Circularly linked list of parameterized type with support for null entries. - COMPLETE

In addition, I want to knock out some implementations of some basic data structure and algorithm problems, just to brush up.

• Dynamic array (ArrayList). - COMPLETE
• Doubly Linked List (LinkedList). - COMPLETE
• Stack (ArrayDeque). - COMPLETE
• Queue (ArrayDeque). - COMPLETE
• Tree. - COMPLETE
• Directed acyclic graph. - COMPLETE
• Heap. - COMPLETE

Most of the above structures will be implemented in something very much like the corresponding Java interfaces. I will be implementing against the interfaces as specified (abridged), but I will be deriving the implementations myself for practice.

The following algorithms will then be implemented, atop the above structures where necessary:

• Binary search through a list. - COMPLETE
• Dynamic programming (http://codercareer.blogspot.com/p/dynamic-interview-questions.html). - COMPLETE
• Preorder and postorder traversal of a tree. - COMPLETE
• Topological sorting of a directed, acyclic graph. - COMPLETE
• Union-find (disjoint set). - COMPLETE
• Bloom filter. - COMPLETE
• Quicksort. - COMPLETE

• Graph coloring. - COMPLETE
• LRU cache. - COMPLETE
• Chess move validator. - COMPLETE
• Maybe something involving Spring, since that has come up a couple times.

• Something involving hashing function distribution, vis a vis numeric analysis.