Data Structures

Core: start here

• Hash TableKey-value storage with average O(1) lookup via a hash function.

• Adjacency List vs MatrixTwo ways to store a graph's edges.
• B-TreeA wide, shallow tree optimized for disks; how database indexes work.
• Binary Search TreeA binary tree ordered so each lookup can halve the search.
• DequeA double-ended queue that adds and removes at both ends.
• Directed Acyclic Graph (DAG)A graph with directed edges and no cycles, as in build systems and pipelines.
• Doubly Linked ListA linked list with pointers in both directions.
• GraphNodes connected by edges; models networks, dependencies and maps.
• Hash CollisionTwo keys hashing to the same slot, and how tables handle it.
• HeapA tree that keeps the min or max at the root; backs priority queues.
• LRU CacheA cache evicting the least recently used item, built from a hash map and a linked list.
• Priority QueueA queue that always returns the highest-priority item first.
• Tree TraversalVisiting tree nodes in pre-order, in-order, post-order or level order.
• TrieA tree of characters for fast prefix lookups.

• Balanced TreeTrees like AVL or red-black that stay shallow for guaranteed O(log n).
• Bloom FilterA compact structure answering "definitely not" or "probably yes" for set membership.
• HyperLogLogEstimating the number of distinct items with tiny memory.
• K-D TreeA tree for searching points in multi-dimensional space.
• Merkle TreeA tree of hashes that verifies large data efficiently.
• Persistent Data StructureAn immutable structure that shares unchanged parts between versions.
• Ring BufferA fixed-size buffer that wraps around.
• Segment TreeA tree for fast range queries over arrays.
• Skip ListA layered linked list with O(log n) search.
• Union-FindTracking which elements belong to the same group.

Nothing here yet.

• Suffix ArrayA sorted array of a string's suffixes for fast substring search.

• Binary TreeA tree where each node has at most two children.
• Data StructureA way of organizing data so certain operations are efficient.
• Dynamic ArrayAn array that grows by reallocating, with amortized O(1) appends.
• Hash FunctionA function mapping data of any size to a fixed-size value.
• Hash TableKey-value storage with average O(1) lookup via a hash function.
• Linked ListNodes pointing to the next node: fast inserts, slow random access.
• QueueA first-in, first-out collection.
• StackA last-in, first-out collection.
• TreeA hierarchy of nodes with one root and no cycles.

• Adjacency List vs MatrixTwo ways to store a graph's edges.
• B-TreeA wide, shallow tree optimized for disks; how database indexes work.
• Binary Search TreeA binary tree ordered so each lookup can halve the search.
• DequeA double-ended queue that adds and removes at both ends.
• Directed Acyclic Graph (DAG)A graph with directed edges and no cycles, as in build systems and pipelines.
• Doubly Linked ListA linked list with pointers in both directions.
• GraphNodes connected by edges; models networks, dependencies and maps.
• Hash CollisionTwo keys hashing to the same slot, and how tables handle it.
• HeapA tree that keeps the min or max at the root; backs priority queues.
• LRU CacheA cache evicting the least recently used item, built from a hash map and a linked list.
• Priority QueueA queue that always returns the highest-priority item first.
• Tree TraversalVisiting tree nodes in pre-order, in-order, post-order or level order.
• TrieA tree of characters for fast prefix lookups.

• Balanced TreeTrees like AVL or red-black that stay shallow for guaranteed O(log n).
• Bloom FilterA compact structure answering "definitely not" or "probably yes" for set membership.
• HyperLogLogEstimating the number of distinct items with tiny memory.
• K-D TreeA tree for searching points in multi-dimensional space.
• Merkle TreeA tree of hashes that verifies large data efficiently.
• Persistent Data StructureAn immutable structure that shares unchanged parts between versions.
• Ring BufferA fixed-size buffer that wraps around.
• Segment TreeA tree for fast range queries over arrays.
• Skip ListA layered linked list with O(log n) search.
• Union-FindTracking which elements belong to the same group.

Nothing here yet.

• Suffix ArrayA sorted array of a string's suffixes for fast substring search.

• Binary TreeA tree where each node has at most two children.
• Data StructureA way of organizing data so certain operations are efficient.
• Dynamic ArrayAn array that grows by reallocating, with amortized O(1) appends.
• Hash FunctionA function mapping data of any size to a fixed-size value.
• Hash TableKey-value storage with average O(1) lookup via a hash function.
• Linked ListNodes pointing to the next node: fast inserts, slow random access.
• QueueA first-in, first-out collection.
• StackA last-in, first-out collection.
• TreeA hierarchy of nodes with one root and no cycles.

• Adjacency List vs MatrixTwo ways to store a graph's edges.
• Binary Search TreeA binary tree ordered so each lookup can halve the search.
• DequeA double-ended queue that adds and removes at both ends.
• Directed Acyclic Graph (DAG)A graph with directed edges and no cycles, as in build systems and pipelines.
• Doubly Linked ListA linked list with pointers in both directions.
• GraphNodes connected by edges; models networks, dependencies and maps.
• Hash CollisionTwo keys hashing to the same slot, and how tables handle it.
• HeapA tree that keeps the min or max at the root; backs priority queues.
• LRU CacheA cache evicting the least recently used item, built from a hash map and a linked list.
• Priority QueueA queue that always returns the highest-priority item first.
• Tree TraversalVisiting tree nodes in pre-order, in-order, post-order or level order.
• TrieA tree of characters for fast prefix lookups.

• B-TreeA wide, shallow tree optimized for disks; how database indexes work.
• Balanced TreeTrees like AVL or red-black that stay shallow for guaranteed O(log n).
• Bloom FilterA compact structure answering "definitely not" or "probably yes" for set membership.
• Persistent Data StructureAn immutable structure that shares unchanged parts between versions.
• Ring BufferA fixed-size buffer that wraps around.

Nothing here yet.

Nothing here yet.