//finds the move which results in best avg score for a given grid
double bestPossibleMove(const Board& board, int depth)
{
if (depth == 0)
{
return hasMove(board) ? findHeuristic(board) : 0;
}
double maxScore = 0;
for(int direction = 0; direction < 4; direction++)
{
Board aiBoard = board;
move(aiBoard, direction);
// if before and after moves are same
if (aiBoard == board)
{
continue;
}
double aiScore = 0;
aiScore = aiSolverMove(aiBoard, depth - 1);
if (aiScore > maxScore)
{
maxScore = aiScore;
}
}
return maxScore;
}
void
initialize(FILE* inputFile, node* initial) {
int i = 0;
while ((fscanf(inputFile, "%d", &(initial->s[i]))) == 1) {
i++;
}
initial->last_action = INITIAL;
initial->g = 0;
initial->f = initial->g + findHeuristic(initial->s);
return;
}
vector<D3DXVECTOR3> AStar::findPath(PathNode* _start, PathNode* _end)
{
//time it for debugging
clock_t clockStart = clock();
//empty the closed set vector
vector<PathNode*>().swap(mClosedSet);
//empty the open set and put in only the start node
vector<PathNode*>().swap(mOpenSet);
mOpenSet.push_back(_start);
//set all node gScores to max
for (PathNode* PN : mPathNodes)
PN->setGScore(INT_MAX);
//set start node properties
_start->setGScore(0);
_start->setFScore(findHeuristic(_start, _end));
//while the open set is not empty
while (mOpenSet.size() > 0)
{
//the node in open set having the lowest f score
PathNode* current;
findLowestFScore(current);
//if we found the goal, return the path
if (current == _end || ((clock() - clockStart) / (float)CLOCKS_PER_SEC) > MAX_PATH_TIME_LOW)
{
vector<D3DXVECTOR3> rePath;
reconstructPath(rePath, _start, current);
return rePath;
}
//save current to closed set
mClosedSet.push_back(current);
//remove current from open set
for (vector<PathNode*>::iterator iter = mOpenSet.begin(); iter != mOpenSet.end(); ++iter)
{
if (*iter == current)
{
mOpenSet.erase(iter);
break;
}
}
//for each linked node in the current node
for (PathNode* PN : current->getLinks())
{
//if it is already in the closed set, continue
if (inClosedSet(PN))
continue;
//find tentative gScore
int tempGScore = current->getGScore() + findHeuristic(current, _end);
//if link node is not in open set or tempGScore < present GScore
if (!inOpenSet(PN) || tempGScore < PN->getGScore())
{
//set the came from of the link to the current node
PN->setCameFrom(current);
//set g score
PN->setGScore(tempGScore);
PN->setFScore(PN->getGScore() + findHeuristic(PN, _end));
//if link is not in open set, add to it
if (!inOpenSet(PN))
mOpenSet.push_back(PN);
}
}
}
//finished loop without finding goal
OutputDebugString(L"ERROR: No path found.");
return vector<D3DXVECTOR3>();
}
//find heuristic between two nodes by looking for it between their positions
int AStar::findHeuristic(PathNode* _start, PathNode* _end)
{
return findHeuristic(_start->getPosition(), _end->getPosition());
}
