private static void TestMatrixMultiply(int n)
{
Console.WriteLine("Test matrix multiply - Loop (n^3) -> Strassen Algorithm (n^log7 or n^2.81):");
var st = new Stopwatch();
var matrix2 = new BigIntegerMatrix(new System.Numerics.BigInteger[n][]);
for (var i = 0; i < n; i++)
{
matrix2[i] = new System.Numerics.BigInteger[n];
for (var j = 0; j < n; j++)
{
matrix2[i][j] = new Random(i * j).Next(100);
}
}
st.Restart();
var resultMat = matrix2 * matrix2;
st.Stop();
Print(resultMat.AsEnumerable());
Console.WriteLine(st.ElapsedMilliseconds);
st.Restart();
resultMat = BigIntegerMatrix.StrassenMultiply(matrix2, matrix2);
st.Stop();
Print(resultMat.AsEnumerable());
Console.WriteLine(st.ElapsedMilliseconds);
}
public BigInteger Calculate(BigInteger n)
{
var basicArray = new[] { new BigInteger[] { 1, 1 }, new BigInteger[] { 1, 0 } };
var matrix = new BigIntegerMatrix(basicArray);
var result = new MatrixNPowerCalculator().Power(matrix, n);
return(result[1][0]);
}
public BigIntegerMatrix Power(BigIntegerMatrix value, BigInteger n)
{
if (n <= 1)
{
return(value);
}
if (n % 2 == 0)
{
var halfValue = Power(value, n / 2);
return(halfValue * halfValue);
}
else
{
var halfValue = Power(value, n / 2);
return(halfValue * halfValue * value);
}
}
