public static void Main(string[] args)
{
while (true)
{
Console.WriteLine("--------------");
Alphametik alphametik = ReadAlphametik();
if (alphametik == null)
{
continue;
}
try
{
SortedList <char, int> assignment = alphametik.Solve();
if (assignment == null)
{
Console.WriteLine("There is no solution for this alphametik.");
}
else
{
PrintAssignment(alphametik, assignment);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}
public SortedList <char, int> Solve()
{
if (this.SymbolTable.Count > 10)
{
throw new Exception("Too many letters.");
}
SortedList <char, int> assignment = new SortedList <char, int>();
switch (this.Operator)
{
case Operator.Addition:
if (this.Result.Length == this.MaximumWordLength + 1)
{
assignment[this.Result[0]] = 1; // this HAS to be 1, for mathematical background see documentation
}
else if (this.Result.Length != this.MaximumWordLength)
{
throw new Exception("The result has to few or to many letters.");
}
break;
case Operator.Multiplication:
int wordSum = this.Words.Sum((s) => s.Length);
if (this.Result.Length != wordSum) // as every word has to start with non-zero the result must be of that length
{
throw new Exception("The result has to few or to many letters.");
}
break;
case Operator.Subtraction: // change alphametik to get same results solving a additive/multiplicative alphametik
case Operator.Division:
{
string[] newWords = new string[this.Words.Length];
Array.Copy(this.Words, newWords, this.Words.Length);
newWords[0] = this.Result;
Alphametik alphametik = new Alphametik(this.Words[0], (Operator)((int)this.Operator - 1), newWords);
return(alphametik.Solve());
}
}
// Start recursive search for solutions
if (SearchRecursive(0, 0, assignment, 0))
{
return(assignment);
}
else
{
return(null);
}
}
private static void PrintAssignment(Alphametik alphametik, SortedList <char, int> assignment)
{
Console.WriteLine("The following assinment solves the alphametik: ");
assignment.All(kvp => { Console.WriteLine("{0} -> {1}", kvp.Key, kvp.Value); return(true); });
string op = "";
switch (alphametik.Operator)
{
case Operator.Addition: op = "+"; break;
case Operator.Subtraction: op = "-"; break;
case Operator.Multiplication: op = "*"; break;
case Operator.Division: op = "/"; break;
}
Console.Write(String.Join(" " + op + " ", alphametik.Words.Select((w) => Alphametik.Convert(w, assignment))));
Console.WriteLine(" = {0}", Alphametik.Convert(alphametik.Result, assignment));
}
