Example #1
0
/*
 * initialize the priority queue with the initial state
 * explored <-- empty
 * loop do
 *      if empty(queue) return failure
 *      node <-- queue.pop()
 *      if node is goal, then return solution(node)
 *      add node to explored
 *      for each action in Action(problem, node) do
 *          child node <-- childnode(problem, node, action)
 *          if child is not in queue or expolored, add node to queue
 *          otherwise, if the child.state is in queue and with a higher pathcost,
 *          then replace that node with the child
 *
 */
bool UCSearch::doSearch(Problem &problem, std::vector<MapNode *> &path)
{
    MapNode *init = problem.getInitState();
    insertQueue(init);

    while(!_queue->isEmpty())
    {
        MapNode *node = _queue->pop();
        if(problem.isGoal(node))
        {
            node->getPathFromRoot(path);
            return true;
        }
        
        insertExplored(node);
        
        std::vector<MovAction_t> & action = problem.getActions();
        std::vector<MovAction_t>::iterator it;
        for(it=action.begin(); it<action.end(); it++)
        {
            if(*it == MOV_ACT_NOOP) {
                continue;
            }

            MapNode *child = NULL;
            int res = 0;
            res = problem.movAction(node, *it, &child);
            if(res == OP_OK)
            {
                if(!isInQueue(child) && !isInExplored(child))
                {
                    insertQueue(child);
                }
                else
                {
                    if(isInQueue(child))
                    {
                        //get old one
                        MapNode *old = findQueueByKey(child->getKey());
                        if(child->getPathCost() < old->getPathCost())
                        {
                            //update;
#ifdef HW1_DEBUG
                            std::cout <<"before update, child cost: " << child->getPathCost();
                            std::cout <<",  old cost: " << old->getPathCost();
#endif
                            updateQueue(old, child);
#ifdef HW1_DEBUG
                            std::cout <<"after,  old cost: " << old->getPathCost();
#endif
                        }
                    }
                }
            }
        }
    }

    return false;
}
Example #2
0
bool BFSearch::doSearch(Problem &problem, std::vector<MapNode *> &path)
{

    MapNode *init = problem.getInitState();
    if(problem.isGoal(init))
    {
        init->getPathFromRoot(path); 
        return true;
    }

    insertQueue(init);

    while(!_queue->isEmpty())
    {
        MapNode * node = getFromQueue();
        insertExplored(node);
        std::vector<MovAction_t> & actions = problem.getActions();
        std::vector<MovAction_t>::iterator it;
        for(it = actions.begin(); it < actions.end(); it++)
        {
            if(*it == MOV_ACT_NOOP) 
            {
                continue;
            }

            MapNode * child = NULL;
            int res = 0;
            res = problem.movAction(node, *it, &child);
            if(res == OP_OK)
            {
                //check if in the queue
                if(!isInQueue(child) && !isInExplored(child))
                {
                    if(problem.isGoal(child))
                    {
                        child->getPathFromRoot(path);
                        return true;
                    }

                    insertQueue(child);
                }
            }
        } //for
    } //while
     
    return false;
}