private static void Main(string[] args)
{
var gen = new Generator();
gen.Iterate();
var rz = gen.Results.OrderBy(p => Math.Abs(p.Key - Math.Round(p.Key))).ThenBy(p => p.Value.Count);
Console.WriteLine("Completed in {0} iterations", gen.IterationCount);
using (var fw = File.CreateText("numbers.html"))
{
fw.WriteLine("<h1>Possible combinations for {0}</h1>", string.Join(", ", gen.Sources));
fw.WriteLine("<table>");
fw.WriteLine("<tr><td>#</td><td>expressions</td></tr>");
foreach (var item in rz)
{
fw.WriteLine("<tr>");
fw.Write("<td>");
fw.WriteLine("{0,3} results for {1}:", item.Value.Count, DecimalToFraction(item.Key));
fw.Write("</td>");
fw.Write("<td style='border-bottom: 1px solid black'>");
foreach (var expression in item.Value)
{
var vc = new EvaluationHashVisitor();
vc.Visit(expression);
fw.WriteLine("{0,20} [{1}]<br/>", expression, vc.DivisionVisitCount);
}
fw.Write("</td>");
fw.Write("</tr>");
}
fw.Write("</table>");
}
}
public void Iterate()
{
var stack = new Stack <Snapshot>();
//seed stack with constant roots
foreach (var constant in Sources)
{
var ss = new Snapshot
{
Tree = Expression.Constant(constant),
AvailableConstants = new List <decimal>(Sources.Where(c => c != constant))
};
ss.ActiveSite = ss.Tree;
stack.Push(ss);
}
//expand tree
while (stack.Count != 0)
{
IterationCount++;
var snapshot = stack.Pop();
var evaluationHashVisitor = new EvaluationHashVisitor();
evaluationHashVisitor.Visit(snapshot.Tree);
if (!snapshot.AvailableConstants.Any())
{
decimal val;
if (Compiled.Contains(evaluationHashVisitor.Hash))
{
continue;
}
Compiled.Add(evaluationHashVisitor.Hash);
try
{
val = Expression.Lambda <Func <decimal> >(snapshot.Tree).Compile()();
}
catch (DivideByZeroException)
{
continue;
}
List <Expression> list;
val = Math.Abs(decimal.Round(val, 4));
if (!Results.TryGetValue(val, out list))
{
list = new List <Expression>();
Results[val] = list;
}
list.Add(snapshot.Tree);
continue;
}
//some constants left, so expand
foreach (var constant in snapshot.AvailableConstants)
{
foreach (var expressionType in _operationTypes)
{
for (int direction = 0; direction < 2; direction++)
{
//dont spawn excessive b*a variant if spawned a*b
if (direction != 0 && (expressionType == ExpressionType.Multiply || expressionType == ExpressionType.Add))
{
continue;
}
var spawn = new Snapshot();
var vtor = new ExpandConstExpressionVisitor(snapshot.ActiveSite,
expressionType,
constant,
direction == 0);
spawn.Tree = vtor.Visit(snapshot.Tree);
spawn.ActiveSite = vtor.ActiveSite;
spawn.AvailableConstants = new List <decimal>(snapshot.AvailableConstants.Where(ac => ac != constant));
stack.Push(spawn);
}
}
}
}
}
