public static void GetAllMatchingSubstringNumbers(BigInteger toFactor)
{
using (StreamWriter sw = new StreamWriter("matchingSubstringNumbers.csv", true))
{
sw.AutoFlush = true;
sw.Write(toFactor.ToString() + ","); // First entry is the number to factor
var substrings = Substrings.SubstringsOf(toFactor.ToString());
/* sw.Write("{"); //Write all substrings for this number
* foreach(BigInteger b in substrings)
* {
* sw.Write(b + ";");
* }
* sw.Write("},");*/
//sw.Write((BigInteger.Pow(2, substrings.Count))+","); // Second entry is the total number of potential factors using this method
for (int i = 1; i < substrings.Count; i++)
{
var potentialFactorPS = PowerSet.PowerSetItemBig <BigInteger>(BigInteger.Pow(2, i), substrings.ToArray()).ToList();
BigInteger potentialFactor = Sum(potentialFactorPS);
if (potentialFactor != 0 && BigInteger.Abs(potentialFactor) != 1 && BigInteger.Abs(potentialFactor) != toFactor && toFactor % potentialFactor == 0)
{
// Console.WriteLine("#" + i + " : " + potentialFactor + " is a factor of " + toFactor);
sw.Write(BigInteger.Pow(2, i) + ",");// Write each Placement in Powerset that matched
}
}
sw.WriteLine();
}
}
/// <summary>
/// Returns a single factor of a given number using the Substring Method or -1 if none are found.
/// </summary>
/// <param name="toFactor">try 119</param>
/// <returns>a single factor</returns>
public static BigInteger GetFactor(BigInteger toFactor)
{
var substrings = Substrings.SubstringsOf(toFactor.ToString());
for (int i = 0; i < (Math.Pow(2, substrings.Count)); i++)
{
var potentialFactorPS = PowerSet.PowerSetItemBig <BigInteger>(i, substrings.ToArray()).ToList();
BigInteger potentialFactor = Sum(potentialFactorPS);
if (potentialFactor != 0 && BigInteger.Abs(potentialFactor) != 1 && BigInteger.Abs(potentialFactor) != toFactor && toFactor % potentialFactor == 0)
{
Console.WriteLine("#" + i + " : " + potentialFactor + " is a factor of " + toFactor);
return(potentialFactor);
}
}
return(-1);
}