public void TestExpressionInteger()
{
var expr = new ExpressionInteger(0, true);
Assert.True(expr.id == 0);
Assert.True(expr.positive);
}
public void TextExpressionOrFlatten()
{
var expr = GenerateTestOr();
var flatten = expr.Flatten();
Assert.Equal(4, flatten.children.Count);
for (int i = 0; i < flatten.children.Count; i++)
{
CheckType <ExpressionInteger> (flatten.children[i]);
ExpressionInteger subexpr = (ExpressionInteger)flatten.children[i];
Assert.Equal(i, subexpr.id);
}
}
private ConstraintOperationResult Propagator(ExpressionInteger left, ExpressionInteger right, Bounds <int> enforce)
{
var result = ConstraintOperationResult.Undecided;
SortedList <int, int> sortedElements;
try
{
//TODO Handle the issue here with repeated array values
sortedElements = SortedElements();
}
catch (Exception)
{
return(result);
}
if (enforce.UpperBound < sortedElements.First().Key || enforce.LowerBound > sortedElements.Last().Key)
{
return(ConstraintOperationResult.Violated);
}
var remove = sortedElements.
TakeWhile(v => v.Key < enforce.LowerBound).
Select(v => v.Value).
Concat(sortedElements.
Reverse().
TakeWhile(v => v.Key > enforce.UpperBound).
Select(v => v.Value)).
ToList();
if (remove.Any())
{
result = ConstraintOperationResult.Propagated;
var domainOperation = default(DomainOperationResult);
foreach (var value in remove)
{
Index.Domain.Remove(value, out domainOperation);
if (domainOperation == DomainOperationResult.EmptyDomain)
{
return(ConstraintOperationResult.Violated);
}
}
left.Bounds = EvaluateBounds(left, null);
}
return(result);
}
private ConstraintOperationResult Propagator(ExpressionInteger left, ExpressionInteger right, Bounds <int> enforce)
{
var result = ConstraintOperationResult.Undecided;
var sortedElements = SortedElements();
if (enforce.UpperBound < sortedElements.First().Key || enforce.LowerBound > sortedElements.Last().Key)
{
return(ConstraintOperationResult.Violated);
}
var remove = sortedElements.
TakeWhile(v => v.Key < enforce.LowerBound).
Select(v => v.Value).
Concat(sortedElements.
Reverse().
TakeWhile(v => v.Key > enforce.UpperBound).
Select(v => v.Value)).
SelectMany(i => i.ToList()).
ToList();
if (remove.Any())
{
result = ConstraintOperationResult.Propagated;
foreach (var value in remove)
{
((IVariable <int>)Index).Remove(value, out DomainOperationResult domainOperation);
if (domainOperation == DomainOperationResult.EmptyDomain)
{
return(ConstraintOperationResult.Violated);
}
}
left.Bounds = EvaluateBounds(left, null);
}
return(result);
}
private Bounds <int> EvaluateBounds(ExpressionInteger left, ExpressionInteger right)
{
var elements = Elements();
return(new Bounds <int>(elements.Min(), elements.Max()));
}
private int Evaluate(ExpressionInteger left, ExpressionInteger right)
{
return(this[Index.Value]);
}
public async Task Solve()
{
await Task.Run(() =>
{
crewCount = names.Count;
flightsCount = crewRequirements.Count;
VariableInteger[,] flightsToPersons = new VariableInteger[flightsCount, crewCount];
for (int i = 0; i < flightsCount; i++)
{
for (int j = 0; j < crewCount; j++)
{
flightsToPersons[i, j] = new VariableInteger("crew" + i.ToString() + j.ToString(), 0, 1);
}
}
var variables = flightsToPersons.Cast <VariableInteger>().ToList();
// Constraints
var constraints = new List <ConstraintInteger>();
// create constraints for each flight
for (int f = 0; f < flightsCount; f++)
{
// size of crew for each flight must be equal to input value
var crewForFlight = new ExpressionInteger[crewCount];
for (int p = 0; p < crewCount; p++)
{
crewForFlight[p] = flightsToPersons[f, p];
}
var flightCrewCount = crewForFlight.Aggregate((a, b) => a + b);
var crewSizesEqual = (flightCrewCount == crewRequirements[f][0]);
constraints.Add(new ConstraintInteger(crewSizesEqual));
// person attributes (is steward, is hostess, speaks french, speaks spanish, speaks german)
// sum of persons with each attribute must be greater than or equal to input value
for (int a = 0; a < 5; a++)
{
crewForFlight = new ExpressionInteger[crewCount];
for (int p = 0; p < crewCount; p++)
{
crewForFlight[p] = (flightsToPersons[f, p] * personsAttributes[p][a]);
}
var sum = crewForFlight.Aggregate((x, y) => x + y);
var attributesGreaterOrEqual = sum >= crewRequirements[f][a + 1];
constraints.Add(new ConstraintInteger(attributesGreaterOrEqual));
}
}
// crew member needs to have 2 flights break after his flight
for (int f = 0; f < flightsCount - 2; f++)
{
for (int i = 0; i < crewCount; i++)
{
var cs = ((flightsToPersons[f, i] + flightsToPersons[f + 1, i] + flightsToPersons[f + 2, i]) <= 1);
constraints.Add(new ConstraintInteger(cs));
}
}
// search for solution
IVariable <int> optimiser = new VariableInteger("optimiser", 1, 100);
IState <int> state = new StateInteger(variables, constraints);
state.StartSearch(out StateOperationResult searchResult, optimiser, out IDictionary <string, IVariable <int> > solution, 10);
if (searchResult == StateOperationResult.Unsatisfiable || searchResult == StateOperationResult.TimedOut)
{
MessageBox.Show("The result is timed out or unsatisfiable", "Crew Allocation Problem",
MessageBoxButton.OK, MessageBoxImage.Error);
}
flightsToNames = new string[flightsCount, maxCrewSize];
for (int i = 0; i < flightsCount; i++)
{
try
{
int count = 0;
for (int j = 0; j < crewCount; j++)
{
if (flightsToPersons[i, j].Value == 1)
{
flightsToNames[i, count] = names[j];
count++;
}
}
}
catch { }
}
});
}
public void AddConstraint(ExpressionInteger constr)
{
Constraints.Add(constr);
}
public ExpressionInteger Not(ExpressionInteger a)
{
return(!a);
}
public ExpressionInteger Or(ExpressionInteger a, ExpressionInteger b)
{
return(a | b);
}
public ExpressionInteger And(ExpressionInteger a, ExpressionInteger b)
{
return(a & b);
}
