core::math::inv_mod

Computes the modular multiplicative inverse of a modulo n. Returns s such that a*s ≡ 1 (mod n) where s is between 1 and n-1 inclusive, or None if gcd(a,n) > 1 (inverse doesn’t exist).

Signature

pub fn inv_mod,
    +Drop,
    +Add,
    +Sub,
    +Mul,
    +DivRem,
    +core::num::traits::Zero,
    +core::num::traits::One,
    +TryInto>,
>(
    a: NonZero, n: NonZero,
) -> Option

Examples

use core::math::inv_mod;

let inv = inv_mod::(3, 7);
assert!(inv == Some(5));