Groups
Category
Level
Stars and Bars counts the ways to distribute n identical items into k distinct bins using combinations.
The Sieve of Eratosthenes marks multiples of each prime to find all primes up to n in O(n log log n) time.
The greatest common divisor (gcd) of two integers is the largest integer that divides both without a remainder.
Gaussian elimination over GF(2) is ordinary Gaussian elimination where addition and subtraction are XOR and multiplication is AND.
A linear recurrence defines each term as a fixed linear combination of a small, fixed number of previous terms.