2.Data Structures

Contiguous indexed storage, constant-time random access, resizing, insertion/deletion costs, and cache locality.

Hashing, buckets, collisions, load factor, resizing, and expected versus worst-case lookup complexity.

Singly/doubly linked lists, insertion/deletion, traversal, pointer techniques, and locality trade-offs.

FIFO queues, dequeues, circular buffers, bounded queues, and priority-queue distinctions.

Uniqueness collections implemented with hashing, balanced trees, bitmaps, or specialized structures.

LIFO storage, push/pop/peek operations, recursion, parsing, monotonic stacks, and implementation choices.

Rooted trees, binary trees, BSTs, balanced trees, traversals, heaps, tries, and B-tree families.

A self-balancing binary search tree with color invariants that keep height logarithmic.

Probabilistic ordered structure with multiple forward-pointer levels and expected logarithmic search/update.

Binary heap representation and priority-queue operations such as push, peek, pop, and heapify.

Compact set membership and counting over dense integer domains using bits.

Probabilistic membership testing with no false negatives for inserted items and tunable false positives.

Graph modeling, adjacency lists/matrices, directed/undirected and weighted graphs, and common traversals/problems.

Disjoint-set union with find/union, path compression, and union by rank/size.

Log-structured merge-tree write path, sorted runs, compaction, read/write amplification, and storage-engine trade-offs.

Historical compact sequential Redis encoding and the general memory-versus-update-cost trade-off of packed representations.

Multiway balanced search trees optimized for block/page-oriented storage and their relationship to B+ trees.

Indexing selected block/range boundary keys to reduce index size while requiring local scans within the selected region.

Why indexes trade extra storage/write work for faster lookup, range, search, or aggregation paths.

Mapping terms to document postings for efficient full-text search.