private Node <TState, TAction> ChildNode(ISearchProblem <TState, TAction> problem, TAction action)
{
var nextState = problem.Result(State, action);
return(new Node <TState, TAction>(
nextState,
action,
this,
problem.PathCost(
PathCost, State, action, nextState
)
));
}
public void Step()
{
if (IsFinished)
{
return;
}
SearchNode <TState, TAction> node;
do
{
if (Frontier.IsEmpty())
{
IsFinished = true;
return;
}
node = Frontier.Pop();
} while (_explored.ContainsKey(node.State));
_explored[node.State] = node;
CurrentState = node.State;
var actions = _problem.GetActions(node.State);
foreach (var action in actions)
{
var childState = _problem.DoAction(node.State, action);
var childCost = node.PathCost + _problem.PathCost(node.State, action);
var child = new SearchNode <TState, TAction>(childState, node, action, childCost);
if (_explored.ContainsKey(childState) || Frontier.ContainsState(childState))
{
continue;
}
if (_problem.IsGoal(childState))
{
CurrentState = childState;
IsFinished = true;
IsSolved = true;
// add goal to explored to allow this.getSolutionTo(goal)
_explored[childState] = child;
}
else
{
Frontier.Push(child);
}
}
}