Math problems in interviews usually reward knowing a small set of reliable patterns. The goal is to avoid brute force by using divisibility, cycles, and modular arithmetic.
Pattern Table
| Problem | Pattern | Lesson |
|---|---|---|
| Prime check | Test only up to sqrt(n) | Prime Check |
| All primes up to n | Sieve marking | Sieve |
| GCD | Euclidean remainder | GCD |
| Power mod | Binary exponentiation | Fast Power |
| Inverse mod | Extended Euclid | Modular Inverse |
FAQs
Do I need advanced math for interviews?
Most interviews need only divisibility, GCD, primes, modular arithmetic, and careful overflow handling.
When does modular inverse exist?
It exists when the number and modulus are coprime.