Math and Geometry (S1)

Coordinate geometry, rectangles, polygons Modular arithmetic and large numbers

Sorting, Greedy and Searching (S2)

Greedy with sorting and exchange arguments Two pointers and sliding window Prefix sums and difference arrays II Binary search on the answer Hash maps and frequency counting

Brute Force and Data Structures (S3)

Complete search and bounds analysis Constructive algorithms Stacks and queues Priority queues and sets Disjoint Set Union

Strings and Graphs

String processing patterns BFS/DFS on structured graphs Trees and rooted traversal Functional graphs and cycle detection Counting and combinatorics

Math and Geometry (S1)

Modular arithmetic and large numbers

common

Work in progress

This module is still being written — the content here is a placeholder. This guide is open source, and contributions are welcome.

Contribute on GitHub — help write this module by opening a pull request.

Coordinate geometry, rectangles, polygons

Coordinate geometry, rectangles, and polygons, anchored on 2021 S1 *Crazy Fencing*, 2020 S1 *Surmising a Sprinter’s Speed*, and 2023 S1 *Trianglane*

Greedy with sorting and exchange arguments

Greedy with sorting and exchange arguments — anchored on 2018 S2 *Sunflowers*, 2017 S2 *High Tide, Low Tide*, and 2015 S2 *Jerseys*

On this page

Modular arithmetic and large numbers