Concepts4

Modular Arithmetic Pitfalls

Modular arithmetic is about working with remainders, but programming languages often return negative remainders, so always normalize with (a % MOD + MOD) % MOD.

#modular arithmetic#modular inverse#fermats little theorem+12

∑MathAdvanced

Discrete Logarithm

The discrete logarithm problem asks for x such that g^x ≡ h (mod p) in a multiplicative group modulo a prime p.

#discrete logarithm#baby-step giant-step#pollard rho dlp+12

∑MathIntermediate

Modular Arithmetic Basics

Modular arithmetic is arithmetic with wrap-around at a fixed modulus m, like numbers on a clock.

#modular arithmetic#mod#modulo c+++12

∑MathIntermediate

Fermat's Little Theorem

Fermat's Little Theorem says that for a prime p and integer a not divisible by p, a^{p-1} ≡ 1 (mod p).

#fermat's little theorem#modular inverse#binary exponentiation+11