public void TestFlipBit()
{
for (int i = 0; i < 10; ++i)
{
BigInteger a = new BigInteger(128, 0, random);
BigInteger b = a;
for (int x = 0; x < 100; ++x)
{
// Note: Intentionally greater than initial size
int pos = random.Next(256);
a = a.FlipBit(pos);
b = b.TestBit(pos) ? b.ClearBit(pos) : b.SetBit(pos);
}
Assert.AreEqual(a, b);
}
for (int i = 0; i < 100; ++i)
{
BigInteger pow2 = one.ShiftLeft(i);
BigInteger minusPow2 = pow2.Negate();
Assert.AreEqual(zero, pow2.FlipBit(i));
Assert.AreEqual(minusPow2.ShiftLeft(1), minusPow2.FlipBit(i));
BigInteger bigI = BigInteger.ValueOf(i);
BigInteger negI = bigI.Negate();
for (int j = 0; j < 10; ++j)
{
string data = "i=" + i + ", j=" + j;
Assert.AreEqual(bigI.Xor(one.ShiftLeft(j)), bigI.FlipBit(j), data);
Assert.AreEqual(negI.Xor(one.ShiftLeft(j)), negI.FlipBit(j), data);
}
}
}