/* (non-Javadoc)
* @see searchingAlgorithms.SearchAlgorithm#search(searchable.Searchable)
*/
@Override
public Solution search(Searchable s) // the function actually implements the search algorithm.
{
addToOpenList(s.getInitialState());
HashSet<State> closedSet =
new HashSet<State>(); // closed list for nodes that we already processed
while (openList.size() > 0) {
State n = popOpenList(); // extracts the first node out of the list
closedSet.add(n);
if (n.equals(s.getGoalState())) {
return backTrace(n, s.getInitialState());
}
ArrayList<State> successors =
new ArrayList<State>(); // creating an array of nodes surroundings a certain node.
successors = s.getAllPossibleStates(n);
n.setFlag(true);
for (State state : successors) { // iterating over all the nodes.
state.setCameFrom(n);
state.setCost(n.getCost() + 1);
if (!closedSet.contains(state) && !openList.contains(state)) {
state.setCameFrom(n);
addToOpenList(state);
} else if (openList.contains(state)) {
State temp = null;
for (State s2 : openList) {
if (s2.getPos().equals(state.getPos())) temp = s2;
}
if (temp != null) {
if (temp.getCost() < state.getCost()) {
openList.remove(temp);
openList.add(state);
}
}
} else openList.add(state);
}
}
return null;
}
/* (non-Javadoc)
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
@Override
public int compareTo(State o) {
return this.getCost() - o.getCost();
}