Jacobi symbol: Difference between revisions

=={{header|Sidef}}==

Also built-in as '''kronecker(n,k)'''.

<lang ruby>func jacobi(n, k) {

assert(k > 0, "#{k} must be positive")

assert(k.is_odd, "#{k} must be odd")

var t = 1

while (n %= k) {

var v = n.valuation(2)

t *= (-1)**v if (k%8 ~~ [3,5])

n >>= v

(n,k) = (k,n)

t = -t if ([n%4, k%4] == [3,3])

}

k==1 ? t : 0

}

for n in (0..50), k in (0..50) {

assert_eq(jacobi(n, 2*k + 1), kronecker(n, 2*k + 1))

}</lang>