/**
* Inserts the node at the tail of the frontier if the corresponding state
* is not already a frontier state and was not yet explored.
*/
protected override void addToFrontier(Node node)
{
if (!explored.Contains(node.getState()) && !frontierStates.Contains(node.getState()))
{
frontier.Enqueue(node);
frontierStates.Add(node.getState());
updateMetrics(frontier.Count);
}
}
/**
* Calls the goal test of the problem and - if the goal test is effectively
* a {@link SolutionChecker} - additionally checks, whether the solution is
* acceptable. Solution checkers can be used to analyze several or all
* solutions with only one search run.
*/
public static bool isGoalState(Problem p, Node n)
{
bool isGoal = false;
GoalTest gt = p.getGoalTest();
if (gt.isGoalState(n.getState()))
{
if (gt is SolutionChecker)
{
isGoal = ((SolutionChecker)gt).isAcceptableSolution(
getSequenceOfActions(n), n.getState());
}
else
{
isGoal = true;
}
}
return isGoal;
}
/**
* Calls the goal test of the problem and - if the goal test is effectively
* a {@link SolutionChecker} - additionally checks, whether the solution is
* acceptable. Solution checkers can be used to analyze several or all
* solutions with only one search run.
*/
public static bool isGoalState(Problem p, Node n)
{
bool isGoal = false;
GoalTest gt = p.getGoalTest();
if (gt.isGoalState(n.getState()))
{
if (gt is SolutionChecker)
{
isGoal = ((SolutionChecker)gt).isAcceptableSolution(
getSequenceOfActions(n), n.getState());
}
else
{
isGoal = true;
}
}
return(isGoal);
}
/**
* Returns the children obtained from expanding the specified node in the
* specified problem.
*
* @param node
* the node to expand
* @param problem
* the problem the specified node is within.
*
* @return the children obtained from expanding the specified node in the
* specified problem.
*/
public List <Node> expand(Node node, Problem problem)
{
List <Node> successors = new List <Node>();
ActionsFunction actionsFunction = problem.getActionsFunction();
ResultFunction resultFunction = problem.getResultFunction();
StepCostFunction stepCostFunction = problem.getStepCostFunction();
foreach (Action action in actionsFunction.actions(node.getState()))
{
System.Object successorState = resultFunction.result(node.getState(), action);
double stepCost = stepCostFunction.c(node.getState(), action, successorState);
successors.Add(createNode(successorState, node, action, stepCost));
}
foreach (NodeListener listener in nodeListeners)
{
listener.onNodeExpanded(node);
}
counter++;
return(successors);
}
/**
* Returns the children obtained from expanding the specified node in the
* specified problem.
*
* @param node
* the node to expand
* @param problem
* the problem the specified node is within.
*
* @return the children obtained from expanding the specified node in the
* specified problem.
*/
public List<Node> expand(Node node, Problem problem)
{
List<Node> successors = new List<Node>();
ActionsFunction actionsFunction = problem.getActionsFunction();
ResultFunction resultFunction = problem.getResultFunction();
StepCostFunction stepCostFunction = problem.getStepCostFunction();
foreach (Action action in actionsFunction.actions(node.getState()))
{
System.Object successorState = resultFunction.result(node.getState(), action);
double stepCost = stepCostFunction.c(node.getState(), action, successorState);
successors.Add(createNode(successorState, node, action, stepCost));
}
foreach (NodeListener listener in nodeListeners)
{
listener.onNodeExpanded(node);
}
counter++;
return successors;
}