What are the main types of data structures?

The main types of data structures are usually divided into several groups:

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#1. Linear structures

Elements go one after another, in sequence.

• Array - fixed size, fast access by index.
• Linked List - fast insertions and deletions, but slow access by index.
• Stack - LIFO principle: last in, first out.
• Queue - FIFO principle: first in, first out.
• Deque - insertion and deletion on both ends.

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#2. Hash structures

Store key-value pairs and give fast access by key.

• Hash Table / Hash Map

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#3. Trees and hierarchical structures

Suited for nested data and fast search.

• Binary Search Tree (BST)
• Balanced trees (AVL, Red-Black Tree)
• Heaps - for priorities and priority queues
• Trie - for words and prefixes

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#4. Graphs

For modeling networks: cities, social networks, routes, connections between objects.

• Directed and undirected graphs
• Weighted and unweighted

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#5. Sets

Store unique elements, convenient for checking "belongs/does not belong".

• Set / HashSet / TreeSet

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#6. Additional structures

Used to speed up search and access.

• Priority queue
• Skip List
• Bloom Filter
• Segment Tree, Fenwick Tree - for working with ranges