C++ PriorityQueue::Top方法代码示例

// Builds the tree
TreeNode<SymbolPriority>* MakeTree(const string& message)
{
	char										currentChar;
	vector<SymbolPriority>						temp;
	PriorityQueue<TreeNode<SymbolPriority>*>	myPriorityQueue;

	for (int i = 0; i < int(message.size()); i++)
	{
		currentChar = message[i];

		if ( temp.empty() )
			temp.push_back( SymbolPriority(currentChar, 1) );
		else if  ( characterExists(temp, currentChar) )
		{
			for (int c = 0; c < int (temp.size()); i++)
				if (currentChar == temp[i].Symbol)
					temp[i].Priority++;
		}
		else
			temp.push_back( SymbolPriority(currentChar, 1) );
	}


	for (int i = 0; i < int(temp.size()); i++)
	{
		if (myPriorityQueue.GetSize() <= 1)
			myPriorityQueue.Push( new TreeNode<SymbolPriority>( temp[i]) );

		else
		{
			char aChar; 
			TreeNode<SymbolPriority>* tempNode;
			// create a new TreeNode<SymbolPriority>* and
			// make the first popped element its left child
			// make the second popped element its right child
			// set its value to the sum of its left and right child priorities

			tempNode->Left = myPriorityQueue.Top();
			aChar = myPriorityQueue.Top()->Data.Priority;
			myPriorityQueue.Pop();

			tempNode->Right = myPriorityQueue.Top(); 
			aChar += myPriorityQueue.Top()->Data.Priority;
			myPriorityQueue.Pop();

			myPriorityQueue.Push( tempNode );
		}
	}

	return myPriorityQueue.Top();
}

/***************************************************************************
 * Que 7. Find the median dynamically for given input array.
 * 
 * Comments : 
 *      1) A median heap can be implemented using two heaps each 
 * 		   containing half the elements.
 * 		2) One the max-heap containing the smallest elements, the
 * 		   other is a min-heap, containing the largest elements.
 * 		3) The size of the max-heap may be equal to the size of 
 * 		   the min-heap.
 * 		4) If the total number of elements are even, the median is
 * 		   the average of the maximum elements of the max-heap and
 * 		   the minimum element of the min heap.
 * 		5) if there are an odd number of elements, the max-heap will 
 * 		   contain one more element than the min-heap. The median in 
 * 		   this case is simply the maximum element of the max-heap.
 * 
 * **************************************************************************/
int FindMedian(int val, int& median, PriorityQueue& right, PriorityQueue& left)
{
  int lcount = left.Size();
  int rcount = right.Size();
  int returnVal = 0;
  
  // both same number of elements after adding one more element
  if(lcount == rcount) 
  {
    if(val < left.Top())
    {
      //Element will go to left
      left.InsertElement(val);
      returnVal = left.Top(); 
    }
    else
    {
      //Element will go to right
      right.InsertElement(val);
      returnVal = right.Top();
    }
  }
  else if( lcount > rcount ) //Left heap has more elements (max heap)
  {
     if(val < left.Top())
     {
       right.InsertElement(left.DeleteTop());
       left.InsertElement(val);
     }
     else
     {
	right.InsertElement(val);
    }
    returnVal = Average(left.Top(),right.Top());
  }
  else if( lcount < rcount ) //Right heap has more elements (min heap)
  {
      if(val < left.Top())
      {
	left.InsertElement(val);
      }
      else
      {
	left.InsertElement(right.DeleteTop());
	right.InsertElement(val);
      }
      returnVal = Average(left.Top(),right.Top());
  }
  return returnVal;
}

void bestFirstSearch(state_t *state) {

    PriorityQueue<state_t> pq;
    pq.Add(0,0,*state);

    state_map_t *map = new_state_map();
    state_map_add(map,state,0);

    state_t currentState;
    state_t child;

    int *cost;
    int ruleid, priority, childCost;
    ruleid_iterator_t iter;

    while (!pq.Empty()) {

        priority = pq.CurrentPriority();

        currentState = pq.Top();
        pq.Pop();    

        nodes++;       

        cost = state_map_get(map,&currentState);

        if (cost == nullptr || priority <= *cost) {

            /* The state added to map is Gray */
            state_map_add(map,&currentState,priority);

            if (is_goal(&currentState)) {
               
                fprintf(output, ": - %i %lu ", priority, nodes);
                destroy_state_map(map);
                return;
            }           

            init_fwd_iter(&iter,&currentState);

            while((ruleid = next_ruleid(&iter)) >= 0) {

                apply_fwd_rule(ruleid,&currentState,&child);

                if (h.getHeuristic(&child) < UINT_MAX) {                
                    childCost = priority + get_fwd_rule_cost(ruleid);
                    state_map_add(map,&child,childCost);
                    pq.Add(childCost,childCost,child);
                }
            }           
        }
    }
    destroy_state_map(map);
    cout << "No goal found.\n";
}

int main( int argc, char **argv )
{
    // VARIABLES FOR INPUT
    char str[ MAX_LINE_LENGTH +1 ] ;
    ssize_t nchars; 
    state_t state; // state_t is defined by the PSVN API. It is the type used for individual states.

    PriorityQueue<state_t> open;
    //state_map_t *map = new_state_map();//******
    // VARIABLES FOR ITERATING THROUGH state's SUCCESSORS
    state_t child;
    ruleid_iterator_t iter; // ruleid_terator_t is the type defined by the PSVN API successor/predecessor iterators.
    int ruleid ; // an iterator returns a number identifying a rule
    int64_t totalNodes;

    // READ A LINE OF INPUT FROM stdin
    printf("Please enter a state followed by ENTER: ");
    if ( fgets(str, sizeof str, stdin) == NULL ) {
        printf("Error: empty input line.\n");
        return 0; 
    }

    // CONVERT THE STRING TO A STATE
    nchars = read_state( str, &state );
    if (nchars <= 0) {
        printf("Error: invalid state entered.\n");
        return 0; 
    }

    printf("The state you entered is: ");
    print_state( stdout, &state );
    printf("\n");

    List StateList = List(); 
   // state_map_add( map, &state, 0 );//******dont know if its a must
    open.Add(0,0,state);
    StateList.add(&state);
    StateList.change_color(&state,1);// Gray
   // StateList.change_distance(&state,0);

    totalNodes = 0;
    int d = 0;
    /* Search */
    while ( !open.Empty() ) {

        // g.n
        d = open.CurrentPriority();
printf("D: %d\n",d);
        state = open.Top();
        open.Pop();

        totalNodes++;

        /* DDD */
        if (StateList.get_color(&state)==0 || (StateList.get_distance(&state)>(d-1))){
            StateList.change_distance(&state,d);
            if (is_goal(&state)==1){
                //PRINT STUFF
                printf("Estado: ");
                print_state( stdout, &state);
                printf(" Estados Generados: %"PRId64" , costo: %d",totalNodes,StateList.get_distance(&state));
                return 1;//SUCCES
            }

            /* expand node */
            init_fwd_iter(&iter, &state);
            while((ruleid = next_ruleid(&iter)) >= 0){
                apply_fwd_rule(ruleid,&state,&child);//'child' is a succesor state_t of 'state'
                StateList.add(&child);
                StateList.change_color(&child, 1);//Gray
                const int child_d = d + get_fwd_rule_cost(ruleid);
                StateList.change_distance( &child , child_d );
                open.Add( child_d , child_d , child );
            }
            StateList.change_color(&state,2); //Black
        }

    }
    printf("FAIL!");
    return 2; //FAIL
}