private static BigInteger CacheableLinear(long n)
{
CacheableBigInteger result = 1;
for (long i = 2; i <= n; i++)
{
result.Multiply(i);
}
return(result);
}
public void OperationsTest()
{
BigInteger initial = BigInteger.Parse("4237894523145135423652643587459827");
BigInteger result0 = initial * 5 * 2 * 10 * 100;
BigInteger result1 = result0 + 50 + 100;
BigInteger result2 = result1 / 10;
BigInteger result3 = result2 - 5;
BigInteger result4 = result3 * 10 * 1000000;
BigInteger result5 = result4 - 1;
BigInteger result6 = result5 / 100;
var cacheable = new CacheableBigInteger(initial);
cacheable.Multiply(5);
cacheable.Multiply(2);
cacheable.Multiply(10);
cacheable.Multiply(100);
cacheable.Add(50);
cacheable.Add(100);
cacheable.Divide(10);
cacheable.Subtract(5);
cacheable.Multiply(10);
cacheable.Multiply(BigInteger.Parse("1000000"));
cacheable.Subtract(BigInteger.Parse("1"));
cacheable.Divide(BigInteger.Parse("100"));
Assert.AreEqual(result6, cacheable.Value);
}
public void OverflowingTest()
{
var cacheable = new CacheableBigInteger(0);
cacheable.Add(long.MaxValue);
cacheable.Add(1);
Assert.AreEqual(new BigInteger(long.MaxValue) + 1, cacheable.Value);
cacheable.Value = new BigInteger(long.MaxValue) + 4;
cacheable.Subtract(long.MaxValue);
cacheable.Subtract(4);
Assert.AreEqual(BigInteger.Zero, cacheable.Value);
cacheable.Value = 1;
cacheable.Multiply(long.MaxValue);
cacheable.Multiply(2);
Assert.AreEqual(new BigInteger(long.MaxValue) * 2, cacheable.Value);
cacheable.Divide(long.MaxValue);
cacheable.Divide(2);
Assert.AreEqual(BigInteger.One, cacheable.Value);
}
private static BigInteger CacheableOptimized(long n)
{
CacheableBigInteger result = 1;
long currentFactor = n;
long currentIncrement = currentFactor - 2;
long bound = n / 2;
for (long i = 1; i <= bound; i++)
{
result.Multiply(currentFactor);
currentFactor += currentIncrement;
currentIncrement -= 2;
}
if (n % 2 == 1)
{
result.Multiply(n / 2 + 1);
}
return(result);
}