public void TestSetBit()
{
Assert.AreEqual(one, zero.SetBit(0));
Assert.AreEqual(one, one.SetBit(0));
Assert.AreEqual(three, two.SetBit(0));
Assert.AreEqual(two, zero.SetBit(1));
Assert.AreEqual(three, one.SetBit(1));
Assert.AreEqual(two, two.SetBit(1));
// TODO Tests for setting bits in negative numbers
// TODO Tests for setting extended bits
for (int i = 0; i < 10; ++i)
{
IBigInteger n = new BigInteger(128, _random);
for (int j = 0; j < 10; ++j)
{
int pos = _random.Next(128);
IBigInteger m = n.SetBit(pos);
bool test = m.ShiftRight(pos).Remainder(two).Equals(one);
Assert.IsTrue(test);
}
}
for (int i = 0; i < 100; ++i)
{
IBigInteger pow2 = one.ShiftLeft(i);
IBigInteger minusPow2 = pow2.Negate();
Assert.AreEqual(pow2, pow2.SetBit(i));
Assert.AreEqual(minusPow2, minusPow2.SetBit(i));
IBigInteger bigI = BigInteger.ValueOf(i);
IBigInteger negI = bigI.Negate();
for (int j = 0; j < 10; ++j)
{
string data = "i=" + i + ", j=" + j;
Assert.AreEqual(bigI.Or(one.ShiftLeft(j)), bigI.SetBit(j), data);
Assert.AreEqual(negI.Or(one.ShiftLeft(j)), negI.SetBit(j), data);
}
}
}
public void TestFlipBit()
{
for (int i = 0; i < 10; ++i)
{
IBigInteger a = new BigInteger(128, 0, _random);
IBigInteger 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)
{
IBigInteger pow2 = one.ShiftLeft(i);
IBigInteger minusPow2 = pow2.Negate();
Assert.AreEqual(zero, pow2.FlipBit(i));
Assert.AreEqual(minusPow2.ShiftLeft(1), minusPow2.FlipBit(i));
IBigInteger bigI = BigInteger.ValueOf(i);
IBigInteger 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);
}
}
}
