public CSP(CSP cspToBeCopied)
{
this.vars = new List<Variable>();
cspToBeCopied.vars.ForEach(v=>this.vars.Add(new Variable(v.pos,v.val,v.remDomain)));
this.domain = cspToBeCopied.domain.ToList();
this.neighbours = new Dictionary<Vector2, List<Variable>>();
foreach (var key in cspToBeCopied.neighbours.Keys)
{
var listNeigh = new List<Variable>();
foreach (var neighSour in cspToBeCopied.neighbours[key])
{
var variableDest = this.vars.First(v => v.pos == neighSour.pos);
listNeigh.Add(variableDest);
}
this.neighbours[key] = listNeigh;
}
this.assignments = new List<Assignment>();
foreach (var ass in cspToBeCopied.assignments)
{
var variableDest = this.vars.First(v => v.pos == ass.variable.pos);
var assignDest = new Assignment(variableDest, ass.value);
assignDest.domainPrune = new Dictionary<Vector2, List<OverFloorType>>();
foreach (var domPruneKey in ass.domainPrune.Keys)
{
var listOfdomainprune = new List<OverFloorType>();
foreach (var valuePruned in ass.domainPrune[domPruneKey])
{
listOfdomainprune.Add(valuePruned);
}
assignDest.domainPrune[domPruneKey] = listOfdomainprune;
}
this.assignments.Add(assignDest);
}
this.toleranceFM = cspToBeCopied.toleranceFM;
this.toleranceFW = cspToBeCopied.toleranceFW;
this.MAC3 = cspToBeCopied.MAC3;
}
/// <summary>
/// Maintenance Arc Consistency, this algorithm will check how many domain prunes are done when a assignemnt is executed
/// </summary>
/// <param name="assign">Assignment to be evaluated and updated</param>
/// <param name="neighbours">List of neighbours to start with (difference between AC3 and MAC3)</param>
/// <returns></returns>
public static bool MAC3(ref Assignment assign,CSP problem)
{
var position = assign.variable.pos;
var variableInLocalProblem = problem.vars.First(v => v.pos == position);
//Add the assignment to the problem
problem.AssignValue(variableInLocalProblem, assign.value,false);
List<Variable> queueToPrune = new List<Variable>();
queueToPrune.Add(variableInLocalProblem);
while (queueToPrune.Any())
{
//Get the first variable
var headVariable = queueToPrune.First();
queueToPrune.Remove(headVariable);
//Get the neighbours of the variable
List<Variable> neighbours = problem.GetNeighbours(headVariable).Where(n => !problem.IsVariableAssigned(n)).ToList();
//Loop over neighbours
foreach (var neigh in neighbours)
{
//Get the list of values to delete for conflict
List<OverFloorType> valuesToPrune = new List<OverFloorType>();
//Check if value is compatible with remaining values in head
foreach (var valPruned in MAC3HeadTailChecker(headVariable, neigh, problem))
{
if (!valuesToPrune.Any(v => v == valPruned))
valuesToPrune.Add(valPruned);
}
//Remove the value from the variable domain in temporal CSP and add to the domain prune
foreach (var prunedVal in valuesToPrune)
{
//Remove domain from variable in problem
problem.RemoveDomainElementFromVariable(neigh, prunedVal);
//remove domain from variable in current variable
neigh.removeDomainElement(prunedVal);
if (!neigh.remDomain.Any())
return false;
//Add prune action to assignment
assign.AddDomainPrune(neigh.pos, prunedVal);
}
if (valuesToPrune.Any())
{
queueToPrune.Add(neigh);
}
}
}
return true;
}
/// <summary>
/// Return the number of remaining values that the assignment will let after being executed
/// </summary>
/// <param name="assign">Assignment to be evaluated </param>
/// <returns>Number of remaining domains values in all remaining variables</returns>
public int ConflictAssignment(Assignment assign)
{
int ret;
if (AssignValue(assign.variable, assign.value))
{
ret = vars.Sum(v => v.remDomain.Count());
RemoveValue(assign.variable);
}
else
ret = int.MaxValue;
return ret;
}
/// <summary>
/// Creates the assignment and prunes other variables
/// </summary>
/// <param name="var">Variable.</param>
/// <param name="val">Value.</param>
/// <returns>True if the assignment is legal</returns>
public bool AssignValue(Variable var,OverFloorType val, bool inference = true)
{
//Create a new assignment
Assignment assign = new Assignment (var, val);
//Get current domain before MAC3 to store posible values to prune
List<OverFloorType> domainBeformMAC = var.remDomain.ToList();
//Get variable prunes
var validAssignment = true;
if (inference)
validAssignment = Search.MAC3(ref assign, new CSP(this) );
if (validAssignment)
{
//Prune all values that are not a variable
assign.domainPrune.Add(var.pos, domainBeformMAC.Where(r => r != val).ToList());
//Go over variable domain prunes to remove from variables
foreach (var varPrune in assign.domainPrune.Keys)
{
List<OverFloorType> valuesToPrune = assign.domainPrune[varPrune];
Variable varToPrune = vars.First(v => v.pos == varPrune);
foreach (var vPrune in valuesToPrune)
{
varToPrune.removeDomainElement(vPrune);
}
}
//Save the assignment
assignments.Add(assign);
}
return validAssignment;
}
