internal RomanNumberInstance(int number, char letter, RomanNumberInstance allowedBeforeNumber, RomanNumberInstance allowedAfterNumber)
{
this.representesNumber = number;
this.representedLetter = letter;
this.allowedBefore = allowedBeforeNumber;
this.allowedAfter = allowedAfterNumber;
}
internal bool AllowedAfter(RomanNumberInstance number)
{
if (number == allowedAfter)
{
return(true);
}
return(false);
}
private static void CreateInstances()
{
if (instances == null)
{
instances = new List <RomanNumberInstance>();
RomanNumberInstance one = new RomanNumberInstance(1, 'I', null, null);
instances.Add(one);
RomanNumberInstance five = new RomanNumberInstance(5, 'V', one, one);
instances.Add(five);
RomanNumberInstance ten = new RomanNumberInstance(10, 'X', one, null);
instances.Add(ten);
RomanNumberInstance fifty = new RomanNumberInstance(50, 'L', ten, ten);
instances.Add(fifty);
RomanNumberInstance hundered = new RomanNumberInstance(100, 'C', ten, null);
instances.Add(hundered);
RomanNumberInstance fivehundered = new RomanNumberInstance(500, 'D', hundered, hundered);
instances.Add(fivehundered);
RomanNumberInstance thousand = new RomanNumberInstance(1000, 'M', hundered, null);
instances.Add(thousand);
}
}
internal static int ConvertToNumber(string RomanNumber)
{
CreateInstances();
char[] characters = RomanNumber.ToCharArray();
RomanNumberInstance highestInstance = null;
int totalNumber = 0;
for (int i = characters.Length - 1; i >= 0; i--)
{
bool found = false;
foreach (RomanNumberInstance instance in instances)
{
if (instance.GetLetter().Equals(characters[i]))
{
found = true;
if (highestInstance == null)
{
highestInstance = instance;
}
else if (highestInstance.GetNumber() < instance.GetNumber())
{
highestInstance = instance;
}
if (highestInstance.GetNumber() > instance.GetNumber())
{
totalNumber -= instance.GetNumber();
}
else
{
totalNumber += instance.GetNumber();
}
}
}
if (found == false)
{
throw new Exception("Character gevonden wat geen bekend romeins nummer is");
}
}
return(totalNumber);
}
internal static string ConvertToRomanSingularNumber(int numberToConvert)
{
if (numberToConvert == 0)
{
return("");
}
CreateInstances();
RomanNumberInstance before = null;
RomanNumberInstance after = null;
foreach (RomanNumberInstance instance in instances)
{
int instanceNumber = instance.GetNumber();
if (numberToConvert == instanceNumber)
{
return("" + instance.GetLetter());
}
if (numberToConvert > instanceNumber)
{
if (before == null || before.GetNumber() < instanceNumber)
{
before = instance;
}
}
if (numberToConvert < instanceNumber)
{
if (after == null || after.GetNumber() > instanceNumber)
{
after = instance;
}
}
}
if (after != null)
{
foreach (RomanNumberInstance instance in instances)
{
if (after.AllowedBefore(instance))
{
if (after.GetNumber() - instance.GetNumber() == numberToConvert)
{
return("" + instance.GetLetter() + after.GetLetter());
}
}
}
}
if (before != null)
{
int amountOfBefores = 2;
while (true)
{
if (before.GetNumber() * amountOfBefores == numberToConvert)
{
string toReturn = "";
for (int i = 0; i < amountOfBefores; i++)
{
toReturn += before.GetLetter();
}
return(toReturn);
}
else if (before.GetNumber() * amountOfBefores > numberToConvert)
{
foreach (RomanNumberInstance instance in instances)
{
if (before.AllowedAfter(instance))
{
int amountOfAfters = 1;
while (true)
{
if (before.GetNumber() + instance.GetNumber() * amountOfAfters == numberToConvert)
{
string toReturn = "" + before.GetLetter();
for (int i = 0; i < amountOfAfters; i++)
{
toReturn += instance.GetLetter();
}
return(toReturn);
}
else if (before.GetNumber() + instance.GetNumber() * amountOfAfters > numberToConvert)
{
throw new NotImplementedException();
}
else
{
amountOfAfters++;
}
}
}
}
}
else
{
amountOfBefores++;
}
}
}
throw new NotImplementedException();
}
