Bubble Sort

Bubble sort (sometimes called sinking sort) is usually the first sorting algorithm you'll encounter when learning to code. It's simple, easy to wrap your head around, stable, and in-place. The catch? Its quadratic time complexity makes it painfully slow for large datasets.

Depth First Search (DFS)

Depth-first search (DFS) is one of those algorithms you'll see everywhere once you start looking: tree traversals, compilers, maze solvers, dependency resolution, finding Strongly Connected Components (SCCs).

Inclusion-Exclusion Principle (IEP)

A deep dive into the Inclusion-Exclusion Principle (IEP) in competitive programming with examples of 2-way, 3-way, and 4-way applications.