public void TestIsPowerOfTwo32()
{
for (int i = 2; i < 31; i++)
{
int x = 1 << i;
Assert.IsTrue(IntegerTheory.IsPowerOfTwo(x), x + " (+)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(x - 1), x + "-1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(x + 1), x + "+1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-x), "-" + x + " (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-x + 1), "-" + x + "+1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-x - 1), "-" + x + "-1 (-)");
}
Assert.IsTrue(IntegerTheory.IsPowerOfTwo(4), "4 (+)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(3), "3 (-)");
Assert.IsTrue(IntegerTheory.IsPowerOfTwo(2), "2 (+)");
Assert.IsTrue(IntegerTheory.IsPowerOfTwo(1), "1 (+)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(0), "0 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-1), "-1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-2), "-2 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-3), "-3 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-4), "-4 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int32.MinValue), "Int32.MinValue (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int32.MinValue + 1), "Int32.MinValue+1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int32.MaxValue), "Int32.MaxValue (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int32.MaxValue - 1), "Int32.MaxValue-1 (-)");
}
public void TestIsPowerOfTwo64()
{
for (int i = 2; i < 63; i++)
{
long x = ((long)1) << i;
Assert.IsTrue(IntegerTheory.IsPowerOfTwo(x), x + " (+)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(x - 1), x + "-1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(x + 1), x + "+1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-x), "-" + x + " (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-x + 1), "-" + x + "+1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(-x - 1), "-" + x + "-1 (-)");
}
Assert.IsTrue(IntegerTheory.IsPowerOfTwo((long)4), "4 (+)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo((long)3), "3 (-)");
Assert.IsTrue(IntegerTheory.IsPowerOfTwo((long)2), "2 (+)");
Assert.IsTrue(IntegerTheory.IsPowerOfTwo((long)1), "1 (+)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo((long)0), "0 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo((long)-1), "-1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo((long)-2), "-2 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo((long)-3), "-3 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo((long)-4), "-4 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int64.MinValue), "Int32.MinValue (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int64.MinValue + 1), "Int32.MinValue+1 (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int64.MaxValue), "Int32.MaxValue (-)");
Assert.IsFalse(IntegerTheory.IsPowerOfTwo(Int64.MaxValue - 1), "Int32.MaxValue-1 (-)");
}
/// <summary>
/// Run example
/// </summary>
public void Run()
{
// 1. Find out whether the provided number is an even number
Console.WriteLine(@"1. Find out whether the provided number is an even number");
Console.WriteLine(@"{0} is even = {1}. {2} is even = {3}", 1, IntegerTheory.IsEven(1), 2, 2.IsEven());
Console.WriteLine();
// 2. Find out whether the provided number is an odd number
Console.WriteLine(@"2. Find out whether the provided number is an odd number");
Console.WriteLine(@"{0} is odd = {1}. {2} is odd = {3}", 1, 1.IsOdd(), 2, IntegerTheory.IsOdd(2));
Console.WriteLine();
// 3. Find out whether the provided number is a perfect power of two
Console.WriteLine(@"2. Find out whether the provided number is a perfect power of two");
Console.WriteLine(@"{0} is power of two = {1}. {2} is power of two = {3}", 5, 5.IsPowerOfTwo(), 16, IntegerTheory.IsPowerOfTwo(16));
Console.WriteLine();
// 4. Find the closest perfect power of two that is larger or equal to 97
Console.WriteLine(@"4. Find the closest perfect power of two that is larger or equal to 97");
Console.WriteLine(97.CeilingToPowerOfTwo());
Console.WriteLine();
// 5. Raise 2 to the 16
Console.WriteLine(@"5. Raise 2 to the 16");
Console.WriteLine(16.PowerOfTwo());
Console.WriteLine();
// 6. Find out whether the number is a perfect square
Console.WriteLine(@"6. Find out whether the number is a perfect square");
Console.WriteLine(@"{0} is perfect square = {1}. {2} is perfect square = {3}", 37, 37.IsPerfectSquare(), 81, IntegerTheory.IsPerfectSquare(81));
Console.WriteLine();
// 7. Compute the greatest common divisor of 32 and 36
Console.WriteLine(@"7. Returns the greatest common divisor of 32 and 36");
Console.WriteLine(IntegerTheory.GreatestCommonDivisor(32, 36));
Console.WriteLine();
// 8. Compute the greatest common divisor of 492, -984, 123, 246
Console.WriteLine(@"8. Returns the greatest common divisor of 492, -984, 123, 246");
Console.WriteLine(IntegerTheory.GreatestCommonDivisor(492, -984, 123, 246));
Console.WriteLine();
// 9. Compute the extended greatest common divisor "z", such that 45*x + 18*y = z
Console.WriteLine(@"9. Compute the extended greatest common divisor Z, such that 45*x + 18*y = Z");
long x, y;
var z = IntegerTheory.ExtendedGreatestCommonDivisor(45, 18, out x, out y);
Console.WriteLine(@"z = {0}, x = {1}, y = {2}. 45*{1} + 18*{2} = {0}", z, x, y);
Console.WriteLine();
// 10. Compute the least common multiple of 16 and 12
Console.WriteLine(@"10. Compute the least common multiple of 16 and 12");
Console.WriteLine(IntegerTheory.LeastCommonMultiple(16, 12));
Console.WriteLine();
}