public void TestHexagonalNthNumber()
{
var expected = 40755;
var actual = HexagonalNumberGenerator.NthNumber(143);
Assert.AreEqual(expected, actual);
}
static void Main(string[] args)
{
// all hexagonal numbers are also triangle numbers
// only need to find next hexagonal number which is also
// a pentagonal number
int p = 166;
int h = 144;
BigInteger pNum = PentagonalNumberGenerator.NthNumber(p);
BigInteger hNum = HexagonalNumberGenerator.NthNumber(h);
while (pNum != hNum && pNum > 0)
{
if (pNum < hNum)
{
p++;
pNum = PentagonalNumberGenerator.NthNumber(p);
}
else
{
h++;
hNum = HexagonalNumberGenerator.NthNumber(h);
}
}
Console.WriteLine(hNum);
Console.ReadKey();
}
public void TestHexagonalNumberGenerator()
{
var expected = new[] { 1, 6, 15, 28, 45 };
var actual = HexagonalNumberGenerator.Generate().Take(5).ToArray();
Assert.AreEqual(expected.Length, actual.Length);
for (int i = 0; i < expected.Length; i++)
{
Assert.AreEqual(expected[i], actual[i]);
}
}
