private void InvertFq()
{
// Verify an example from the NTRU tutorial
IntegerPolynomial a = new IntegerPolynomial(new int[] { -1, 1, 1, 0, -1, 0, 1, 0, 0, 1, -1 });
IntegerPolynomial b = a.InvertFq(32);
AssertEqualsMod(new int[] { 5, 9, 6, 16, 4, 15, 16, 22, 20, 18, 30 }, b.Coeffs, 32);
VerifyInverse(a, b, 32);
// test 3 random polynomials
int numInvertible = 0;
while (numInvertible < 3)
{
a = (IntegerPolynomial)PolynomialGeneratorForTesting.generateRandom(853);
b = a.InvertFq(2048);
if (b != null)
{
numInvertible++;
VerifyInverse(a, b, 2048);
}
}
// test a non-invertible polynomial
a = new IntegerPolynomial(new int[] { -1, 0, 1, 1, 0, 0, -1, 0, -1, 0, 1 });
b = a.InvertFq(32);
if (b != null)
throw new Exception("IntegerPolynomialTest InvertFq test failed!");
}