The non-number-theoretic maths: counting, chance, and linear algebra.
Counting
- General — pigeonhole and friends
- Combinatorics — permutations, combinations, stars and bars, inclusion-exclusion
- Burnside’s Lemma and Pólya Enumeration
- Catalan and Other Special Numbers
- Generating Functions
Probability
- Probability — expectation, linearity, conditional
- Expected Value Techniques
- Probability DP
Algebra
- Binary Exponentiation
- Modular Arithmetic
- Matrices
- Matrix Exponentiation
- Determinant
- Rank and Linear Systems
- Linear Basis / XOR Basis
- Gaussian Elimination · Gauss-Jordan
See also: Number Theory · Polynomial / Algebra