public static bool TryConvertToRationalNumber(decimal num, out IQ.RationalNumber rational)
{
rational = IQ.New(0, 0);
int wholePart = (int)decimal.Truncate(num);
decimal decimalPlaces = num - (decimal)wholePart;
var numString = decimalPlaces.ToString();
var totalLength = numString.Length;
var placesCount = DecimalPlacesCount(decimalPlaces);
if (placesCount == 28)
{
numString = numString.Remove(numString.Length - 1) + (int.Parse(numString.Substring(numString.Length - 1, 1)) - 1);
decimalPlaces = decimal.Parse(numString);
}
bool repeatingConfirmed = false;
bool isNegative = decimalPlaces < 0;
string first = "";
int firstIndex = 0;
string second = "";
int secondIndex = 0;
int repeatingPartLength = 0;
int nonPlacesLength = numString.Length - placesCount;
bool isEqualFirstTime = false;
int repeatCount = 0;
bool isRepeating = true;
for (int i = 0; i < (decimal)placesCount / 2; i++)
{
repeatCount = 0;
isRepeating = true;
isEqualFirstTime = false;
repeatingPartLength = i + 1;
for (int j = 0; (isEqualFirstTime ? (j + 2) * repeatingPartLength : j + (2 * repeatingPartLength)) <= placesCount; j++)
{
if (isEqualFirstTime)
{
secondIndex = secondIndex + repeatingPartLength;
}
else
{
firstIndex = nonPlacesLength + j;
secondIndex = firstIndex + repeatingPartLength;
}
first = numString.Substring(firstIndex, repeatingPartLength);
second = numString.Substring(secondIndex, repeatingPartLength);
if (string.Equals(first, second))
{
if (!isEqualFirstTime && firstIndex < placesCount)
{
isEqualFirstTime = true;
}
else
{
repeatCount++;
if (repeatCount > 2)
{
break;
}
}
}
else if (isEqualFirstTime)
{
isEqualFirstTime = false;
isRepeating = false;
}
}
if (isEqualFirstTime && isRepeating)
{
repeatingConfirmed = true;
break;
}
}
if (!repeatingConfirmed)
{
//Try to find repeating part don't fit in decimal places
repeatCount = 0;
isRepeating = true;
isEqualFirstTime = false;
int lastIndexOfOccurance = 0;
for (int i = 0; i < (decimal)placesCount / 2; i++)
{
firstIndex = totalLength;
repeatingPartLength = i + 1;
first = numString.Substring(firstIndex - repeatingPartLength, repeatingPartLength);
var indexOfOccurance = numString.IndexOf(first);
if (indexOfOccurance > 0 && indexOfOccurance != (firstIndex - repeatingPartLength))
{
lastIndexOfOccurance = indexOfOccurance;
if (!isEqualFirstTime)
{
isEqualFirstTime = true;
}
else
{
repeatCount++;
}
}
else if (i == 0)
{
isRepeating = false;
break;
}
else if (isEqualFirstTime)
{
var repeatingPart = numString.Substring(lastIndexOfOccurance, (firstIndex - repeatingPartLength + 1) - lastIndexOfOccurance);
firstIndex = lastIndexOfOccurance;
repeatingPartLength = repeatingPart.Length;
repeatingConfirmed = true;
break;
}
}
}
if (repeatingConfirmed)
{
//first index = non repeating part
//get int with Math.Truncate(decimal)
int placesIndex = firstIndex - nonPlacesLength;
//ulong firstMultiplier = (ulong)Math.Pow((double)10, (double)placesIndex + (double)repeatingPartLength);
decimal firstNum = decimalPlaces;
decimal firstMultiplier = 1;
for (int i = 0; i < repeatingPartLength + placesIndex; i++)
{
firstNum *= 10;
firstMultiplier *= 10;
}
//ulong secondMultiplier = (ulong)Math.Pow((double)10, (double)placesIndex);
//decimal secondNum = secondMultiplier * decimalPlaces;
decimal secondMultiplier = 1;
for (int i = 0; i < repeatingPartLength; i++)
{
secondMultiplier *= 10;
}
decimal remaininMultiplier = firstMultiplier - secondMultiplier;
if (remaininMultiplier == 0)
{
return(false);
}
decimal remainingNum = (decimal.Truncate(firstNum));
decimal gcd = GetGCD(remainingNum, remaininMultiplier);
int numerator = remainingNum / gcd >= (decimal)int.MaxValue ? 0 : (int)(remainingNum / gcd);
if (numerator == 0)
{
return(false);
}
if (isNegative)
{
numerator = -numerator;
}
int denominator = remaininMultiplier / gcd >= (decimal)int.MaxValue ? 0 : (int)(remaininMultiplier / gcd);
rational = IQ.New(numerator, denominator);
return(true);
}
else
{
decimal firstMultiplier = (ulong)Math.Pow((double)10, (double)placesCount);
decimal firstNum = (ulong)((decimal)firstMultiplier * decimalPlaces);
decimal gcd = GetGCD(firstNum, firstMultiplier);
if (gcd > 0)
{
var simplifiedFirstNum = (int)(firstNum / gcd);
var simplifiedFirstMultiplier = (int)(firstMultiplier / gcd);
rational = IQ.New((isNegative ? -simplifiedFirstNum : simplifiedFirstNum), simplifiedFirstMultiplier);
return(true);
}
else
{
return(false);
}
}
}
public static RealNumber New(IQ.RationalNumber r)
{
return(new RealNumber(numerator: r.N, denominator: r.D));
}