pgcd ( p q -- a d )
Polynomials

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Vocabulary
math.polynomials

Inputs

p	a polynomial
q	a polynomial

Outputs

a	a polynomial
d	a polynomial

Word description
Computes the greatest common divisor d of p and q, and another value a satisfying:

a*q = d mod p

Notes
GCD in the case of polynomials is a monic polynomial of the highest possible degree that divides into both p and q.

Examples

USING: kernel math.polynomials prettyprint ; { 1 1 1 1 } { 1 1 } pgcd [ . ] bi@
{ 0 0 } { 1 1 }

Definition

USING: arrays kernel math.polynomials.private ;

IN: math.polynomials

: pgcd ( p q -- a d )
    [ V{ 0 } clone V{ 1 } clone ] 2dip swap (pgcd)
    [ >array ] bi@ ;