# Data Structures - [Arrays](https://interviews.woojiahao.com/data-structures/arrays.md): Array problems are by far the most common type of algorithm problems I have encountered. There are a few techniques that are used very commonly so it is best to familiarize yourself with all of them - [Matrices](https://interviews.woojiahao.com/data-structures/arrays/matrices.md): Matrix problems are quite common and are relatively straightforward, just focus on understanding the techniques required - [Strings](https://interviews.woojiahao.com/data-structures/strings.md): String problems are very similar to array problems as they both use very similar techniques but there are some slight differences - [Linked Lists](https://interviews.woojiahao.com/data-structures/linked-lists.md): Linked lists are useful when paired with hash tables as it allows search/insertion in O(1) time and they can also be used alone to solve problems - [Doubly Linked Lists](https://interviews.woojiahao.com/data-structures/linked-lists/doubly-linked-lists.md): Doubly linked lists hold references to both the previous and next elements - [Hash Tables](https://interviews.woojiahao.com/data-structures/hash-tables.md): Hash tables are a corner stone of data structures for most problems, they are useful when there are unique keys with given values - [Graphs](https://interviews.woojiahao.com/data-structures/graphs.md): Graph problems are plentiful but the core data structure does have some unique techniques that can be applied to it - [Trees](https://interviews.woojiahao.com/data-structures/graphs/trees.md): Trees are special types of graphs that have exactly N - 1 edges with exactly one path between nodes. They are one of the most common category of problems so it is a must to master them - [Binary Search Trees](https://interviews.woojiahao.com/data-structures/graphs/trees/binary-search-trees.md): Binary Search Trees are the first of many specialized trees - [Heaps](https://interviews.woojiahao.com/data-structures/graphs/trees/heaps.md): Heaps or priority queues are a very powerful data structure that can be used to easily store information that has some intrinsic order - [Tries](https://interviews.woojiahao.com/data-structures/graphs/trees/tries.md): Tries are special types of trees that make searching and storing strings more efficient - [Segment Trees](https://interviews.woojiahao.com/data-structures/graphs/trees/segment-trees.md): Segment trees are a unique application of trees that help to solve problems that involve many range queries over an array - [Stacks](https://interviews.woojiahao.com/data-structures/stacks.md): Stack problems usually come in the form of monotonic stack problems - [Queues](https://interviews.woojiahao.com/data-structures/queues.md): Queue problems are less common but it is still a data structure that is worth understanding well - [Double Ended Queues](https://interviews.woojiahao.com/data-structures/queues/double-ended-queues.md) - [Union-Find Disjoint Set (UFDS)](https://interviews.woojiahao.com/data-structures/union-find-disjoint-set-ufds.md): UFDS is a straightforward but powerful data structure often used to determine when data is in the same set as one another --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://interviews.woojiahao.com/data-structures.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.