Concepts4

Problem Classification Patterns

Many competitive programming problems map to a small set of classic patterns; recognizing keywords and constraints lets you pick the right tool fast.

#problem classification#binary search on answer#two pointers+12

⚙️AlgorithmIntermediate

Offline Query Processing

Offline query processing means you collect all queries first and answer them later in a smart order that makes updates/queries cheap.

#offline query processing#mo's algorithm#fenwick tree+12

⚙️AlgorithmAdvanced

Sqrt Decomposition on Queries

Sqrt decomposition on queries (time blocking) processes Q operations in blocks of size about \(\sqrt{Q}\) to balance per-query overhead and rebuild cost.

#sqrt decomposition#time blocking#query blocking+12

⚙️AlgorithmIntermediate

Mo's Algorithm

Mo's algorithm answers many range queries offline by reordering them to minimize pointer movement along the array.

#mo's algorithm#offline queries#range queries+12