MazeWalker::MazeWalker(char** mazePtr, int startRow, int startCol, int rows, int cols, bool dfs): m_startPos(startRow,startCol) , m_curPos(startRow,startCol){
m_maze = mazePtr;
m_rows = rows;
m_cols = cols;
m_isDFS = dfs;
m_noExit = false;
m_visited = new bool *[m_rows];
for(int i = 0; i < m_rows; i++){
m_visited[i] = new bool[m_cols];
for(int j = 0; j<m_cols; j++){
m_visited[i][j] = false;
}
}
Position firstMove = Position(startRow,startCol);
move(firstMove);
walkMaze();
}
bool MazeWalker::walkMaze()
{
/*
set up position;
beware that value may exceed or less than the m_rows and m_cols,
so we need to set conditions to check
*/
char up_ = 'n'; char right_ = 'n'; char down_ = 'n'; char left_ = 'n';
//direction_ is the character at the specific location w.r.t the m_curPos to the maze
//So the first time this method is called, it's at the start position
if(m_curPos.getRow()-1 >= 0)
up_ = m_maze[ m_curPos.getRow()-1 ][ m_curPos.getCol() ];
if(m_curPos.getCol()+1 < m_cols)
right_ = m_maze[ m_curPos.getRow() ][ m_curPos.getCol()+1 ];
if(m_curPos.getRow()+1 < m_rows)
down_ = m_maze[ m_curPos.getRow()+1 ][ m_curPos.getCol() ];
if(m_curPos.getCol()-1 >= 0)
left_ = m_maze[ m_curPos.getRow() ][ m_curPos.getCol()-1 ];
//positions ---- use to check if they exceeds the boundary of the maze
int up_move = m_curPos.getRow()-1;
int right_move = m_curPos.getCol()+1;
int down_move = m_curPos.getRow()+1;
int left_move = m_curPos.getCol()-1;
if(m_searchType == Search::DFS)
{
if(isGoalReached())
{
while(m_moveStack.size() > 0)
m_moveStack.pop();
return true;
}
else
{
if((up_ == 'P' || up_ == 'E') && up_move >= 0) //so it's within range
{
Position up = Position( m_curPos.getRow()-1 , m_curPos.getCol() );
m_moveStack.push(up);
}
if((right_ == 'P' || right_ == 'E') && right_move < m_cols) //so it's within range
{
Position right = Position( m_curPos.getRow() , m_curPos.getCol()+1 );
m_moveStack.push(right);
}
if((down_ == 'P' || down_ == 'E') && down_move < m_rows) //so it's within range
{
Position down = Position( m_curPos.getRow()+1 , m_curPos.getCol() );
m_moveStack.push(down);
}
if((left_ == 'P' || left_ == 'E') && left_move >= 0 ) //so it's within range
{
Position left = Position( m_curPos.getRow() , m_curPos.getCol()-1 );
m_moveStack.push(left);
}
while(m_moveStack.size() > 0)
{
Position temp = Position(m_moveStack.top().getRow(), m_moveStack.top().getCol());
m_moveStack.pop(); //pop
if( m_visited[ temp.getRow() ][ temp.getCol() ] == 0 )
{ move(temp); //move to that temporary position
storeValidMoves(); //mark as visited
walkMaze();
}
}//endwhile
}//end else
}//end if DFS
if(m_searchType == Search::BFS)
{
m_moveQueue.push(m_curPos); //EnQueue( m.StartNode )
while(m_moveQueue.size() > 0)
{
m_curPos = Position(m_moveQueue.front().getRow(), m_moveQueue.front().getCol());
//store valid moves after first run
if(m_curPos.getRow() != m_startPos.getRow() || m_curPos.getCol() != m_startPos.getCol())
storeValidMoves();
//conditions
if(m_curPos.getRow()-1 >= 0)
up_ = m_maze[ m_curPos.getRow()-1 ][ m_curPos.getCol() ];
else
up_ = 'n';
if(m_curPos.getCol()+1 < m_cols)
right_ = m_maze[ m_curPos.getRow() ][ m_curPos.getCol()+1 ];
else
right_ = 'n';
if(m_curPos.getRow()+1 < m_rows)
down_ = m_maze[ m_curPos.getRow()+1 ][ m_curPos.getCol() ];
else
down_ = 'n';
if(m_curPos.getCol()-1 >= 0)
left_ = m_maze[ m_curPos.getRow() ][ m_curPos.getCol()-1 ];
else
left_ = 'n';
int up_move = m_curPos.getRow()-1;
int right_move = m_curPos.getCol()+1;
int down_move = m_curPos.getRow()+1;
int left_move = m_curPos.getCol()-1;
m_moveQueue.pop();
if(isGoalReached())
{
while(m_moveQueue.size() > 0)
{
m_moveQueue.pop();
}
return true;
}
else
{
//first, we need to store all valid neighbors into the queue
//for each neighbor: up - right - down - left
if((up_ == 'P' || up_ == 'E') && up_move >= 0) //so it's within range
{
//create a position
Position up = Position( m_curPos.getRow()-1 , m_curPos.getCol() );
//push to quene
if( m_visited[ up.getRow() ][ up.getCol() ] == 0 )
m_moveQueue.push(up);
}
if((right_ == 'P' || right_ == 'E') && right_move < m_cols) //so it's within range
{
Position right = Position( m_curPos.getRow() , m_curPos.getCol()+1 );
if( m_visited[ right.getRow() ][ right.getCol() ] == 0 )
m_moveQueue.push(right);
}
if((down_ == 'P' || down_ == 'E') && down_move < m_rows) //so it's within range
{
Position down = Position( m_curPos.getRow()+1 , m_curPos.getCol() );
if( m_visited[ down.getRow() ][ down.getCol() ] == 0 )
m_moveQueue.push(down);
}
if((left_ == 'P' || left_ == 'E') && left_move >= 0 ) //so it's within range
{
Position left = Position( m_curPos.getRow() , m_curPos.getCol()-1 );
if( m_visited[ left.getRow() ][ left.getCol() ] == 0 )
m_moveQueue.push(left);
}
}//end else
}//end while
}
return false;
}
