Function winter_math::polynom::syn_div_in_place

pub fn syn_div_in_place<E>(p: &mut [E], a: usize, b: E) where
    E: FieldElement, 

Divides a polynomial by a polynomial of special form and saves the result into the original polynomial.

Specifically, divides polynomial p by polynomial (x^a - b) using synthetic division method and saves the result into p. If the polynomials don’t divide evenly, the remainder is ignored. Polynomial p is expected to be in the coefficient form, and the result will be in coefficient form as well.

This function is significantly faster than the generic polynom::div() function, and as compared to polynom::syn_div() function, this function does not allocate any additional memory.

Panics

Panics if:

• a is zero;
• b is zero;
• p.len() is smaller than or equal to a.

Examples

// p(x) = x^3 + x^2 + 2 * x + 2
let mut p = [
    BaseElement::new(2),
    BaseElement::new(2),
    BaseElement::new(1),
    BaseElement::new(1),
];

// divide by x + 1
syn_div_in_place(&mut p, 1, -BaseElement::ONE);

// expected result = x^2 + 2
let expected = [
    BaseElement::new(2),
    BaseElement::ZERO,
    BaseElement::new(1),
    BaseElement::ZERO,
];

assert_eq!(expected, p);