// function ONLINE-DFS-AGENT(s') returns an action
// inputs: s', a percept that identifies the current state
public override Action execute(Percept psDelta)
{
object sDelta = ptsFunction.getState(psDelta);
// if GOAL-TEST(s') then return stop
if (goalTest(sDelta))
{
a = NoOpAction.NO_OP;
}
else
{
// if s' is a new state (not in untried) then untried[s'] <-
// ACTIONS(s')
if (!untried.ContainsKey(sDelta))
{
untried.Add(sDelta, actions(sDelta));
}
// if s is not null then do
if (null != s)
{
// Note: If I've already seen the result of this
// [s, a] then don't put it back on the unbacktracked
// list otherwise you can keep oscillating
// between the same states endlessly.
if (!(sDelta.Equals(result.get(s, a))))
{
// result[s, a] <- s'
result.put(s, a, sDelta);
// Ensure the unbacktracked always has a list for s'
if (!unbacktracked.ContainsKey(sDelta))
{
unbacktracked.Add(sDelta, new List <object>());
}
// add s to the front of the unbacktracked[s']
unbacktracked[sDelta].Add(s);
}
}
// if untried[s'] is empty then
if (untried[sDelta].Capacity == 0)
{
// if unbacktracked[s'] is empty then return stop
if (unbacktracked[sDelta].Capacity == 0)
{
a = NoOpAction.NO_OP;
}
else
{
// else a <- an action b such that result[s', b] =
// POP(unbacktracked[s'])
object popped = unbacktracked[sDelta].Remove(0);
foreach (Pair <object, Action> sa in result.Keys)
{
if (sa.getFirst().Equals(sDelta) && result[sa].Equals(popped))
{
a = sa.getSecond();
break;
}
}
}
}
else //Needs debugging.
{
// else a <- POP(untried[s'])
//a = untried[sDelta].Remove(0);
}
}
if (a.isNoOp())
{
// I'm either at the Goal or can't get to it,
// which in either case I'm finished so just die.
setAlive(false);
}
// s <- s'
s = sDelta;
// return a
return(a);
}
// function LRTA*-AGENT(s') returns an action
// inputs: s', a percept that identifies the current state
public override Action execute(Percept psDelta)
{
object sDelta = ptsFunction.getState(psDelta);
// if GOAL-TEST(s') then return stop
if (goalTest(sDelta))
{
a = NoOpAction.NO_OP;
}
else
{
// if s' is a new state (not in H) then H[s'] <- h(s')
if (!H.ContainsKey(sDelta))
{
H.Add(sDelta, getHeuristicFunction().h(sDelta));
}
// if s is not null
if (null != s)
{
// result[s, a] <- s'
result.put(s, a, sDelta);
// H[s] <- min LRTA*-COST(s, b, result[s, b], H)
// b (element of) ACTIONS(s)
double minimum = double.MaxValue;
foreach (Action b in actions(s))
{
double cost = lrtaCost(s, b, result.get(s, b));
if (cost < minimum)
{
minimum = cost;
}
}
H.Add(s, minimum);
}
// a <- an action b in ACTIONS(s') that minimizes LRTA*-COST(s', b,
// result[s', b], H)
double min = double.MaxValue;
// Just in case no actions
a = NoOpAction.NO_OP;
foreach (agent.Action b in actions(sDelta))
{
double cost = lrtaCost(sDelta, b, result.get(sDelta, b));
if (cost < min)
{
min = cost;
a = b;
}
}
}
// s <- s'
s = sDelta;
if (a.isNoOp())
{
// I'm either at the Goal or can't get to it,
// which in either case I'm finished so just die.
setAlive(false);
}
// return a
return(a);
}
