static Expression ToSAT(List <_3COL.Node> nodes)
{
curVariables = new List <Variable>();
AndOperator and = null;
// Jeder Knoten muss mindestens eine Farbe haben
foreach (var node in nodes)
{
OrOperator or = null;
foreach (var color in colors)
{
if (or == null)
{
or = new OrOperator(Vari(node, color), null);
}
else if (or.Right == null)
{
or.Right = Vari(node, color);
}
else
{
or = new OrOperator(or, Vari(node, color));
}
}
if (and == null)
{
and = new AndOperator(or, null);
}
else if (and.Right == null)
{
and.Right = or;
}
else
{
and = new AndOperator(and, or);
}
}
// Jeder Knoten darf maximal eine Farbe haben
foreach (var node in nodes)
{
foreach (var c1 in colors)
{
foreach (var c2 in colors)
{
if (c1 == c2)
{
continue;
}
and = new AndOperator(and,
new NotOperator(
new AndOperator(
Vari(node, c1),
Vari(node, c2))));
}
}
}
// Mein Nachbar darf nicht die selbe farbe haben
foreach (var conn in connections)
{
foreach (var c in colors)
{
and = new AndOperator(and,
new NotOperator(
new AndOperator(
Vari(conn.Item1, c),
Vari(conn.Item2, c))));
}
}
string s = and.ToString();
return(and);
}
