/// <summary>
/// Creates and returns an integer variable that represents the difference of <paramref name="a"/> and <paramref name="b"/>
/// </summary>
public static IntegerVariable Subtract(IntegerVariable a, IntegerVariable b)
{
IntegerVariable difference = new IntegerVariable(a.ConstraintThingySolver, null, IntegerVariable.DefaultRange);
Constraint.InRange(difference, a.AllowableValues - b.AllowableValues);
Difference(difference, a, b);
return(difference);
}
/// <summary>
/// Creates and returns an integer variable that represents the sum of <paramref name="a"/> and <paramref name="b"/>
/// </summary>
public static IntegerVariable Add(IntegerVariable a, IntegerVariable b)
{
IntegerVariable sum = new IntegerVariable(a.ConstraintThingySolver, null, IntegerVariable.DefaultRange);
Constraint.InRange(sum, a.AllowableValues + b.AllowableValues);
Sum(sum, a, b);
return(sum);
}
/// <summary>
/// Constrains <paramref name="variable" /> to be in <paramref name="range"/>
/// </summary>
public static void InRange(IntegerVariable variable, IntegerInterval range)
{
variable.BackdoorSet(IntegerInterval.Intersection(variable.AllowableValues, range));
}
/// <summary>
/// Constraints <paramref name="variable"/> to be exactly <paramref name="value"/>
/// </summary>
public static void Equal(IntegerVariable variable, int value)
{
InRange(variable, value, value);
}
/// <summary>
/// Creates and returns an integer variable that represents the difference of <paramref name="a"/> and <paramref name="b"/>
/// </summary>
public static void Difference(IntegerVariable difference, IntegerVariable a, IntegerVariable b)
{
new IntegerDifferenceConstraint(difference, a, b);
}
/// <summary>
/// Constrains <paramref name="sum"/> to be the sum of <paramref name="a"/> and <paramref name="b"/>
/// </summary>
public static void Sum(IntegerVariable sum, IntegerVariable a, IntegerVariable b)
{
new IntegerSumConstraint(sum, a, b);
}
/// <summary>
/// Constrains that the values of <paramref name="a"/> and <paramref name="b"/> are not equal.
/// </summary>
public static void NotEqual(IntegerVariable a, IntegerVariable b)
{
new IntegerInequalityConstraint(a, b);
}
/// <summary>
/// Constrains <paramref name="variable"/> to be at least <paramref name="value"/>
/// </summary>
public static void GreaterThanOrEqual(IntegerVariable variable, int value)
{
InRange(variable, value, int.MaxValue);
}
/// <summary>
/// Constraints <paramref name="variable"/> to be at most <paramref name="value"/>
/// </summary>
public static void LessThanOrEqual(IntegerVariable variable, int value)
{
InRange(variable, int.MinValue, value);
}
/// <summary>
/// Constrains <paramref name="variable"/> to be between <paramref name="minValue"/> and <paramref name="maxValue"/>
/// </summary>
public static void InRange(IntegerVariable variable, int minValue, int maxValue)
{
InRange(variable, new IntegerInterval(minValue, maxValue));
}