benchmarks/Algorithms/modular_mul/problem.md

Overflow-Safe Modular Multiplication

Description

Compute the signed modular product of two integers by repeated doubling without directly multiplying them.

Input

The function receives integers $a$, $b$, and a positive modulus.

Output

Return a representative congruent to $ab$ modulo the modulus.

Constraints

• $-modulus < a < modulus$.
• b fits signed C int.
• $0 < modulus$ and $2,modulus \le \texttt{INT_MAX}$.

Source

Classical modular-arithmetic problem reconstructed from the verified C artifact.