gmp_gcdext

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

gmp_gcdext — Calcola il MCD e moltiplicatori

Descrizione

gmp_gcdext(resource $a, resource $b): array

Calcola g, s e t, in questo modo a*s + b*t = g = gcd(a,b), dove MCD è il massimo comune divisore. Restituisce un array con i rispettivi argomenti, cioè, g, s e t.

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FatPhil ¶

21 years ago

The extended GCD can be used to calculate mutual modular inverses of two
coprime numbers. Internally gmp_invert uses this extended GCD routine, 
but effectively throws away one of the inverses.

If gcd(a,b)=1, then r.a+s.b=1
Therefore  r.a == 1 (mod s) and s.b == 1 (mod r)
Note that one of r and s will be negative, and so you'll want to
canonicalise it.

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