bool move(int tile)
{
  //  int temp;

    int blankrow;
    int blankcol;

    int tilerow;
    int tilecol;

    for (int row = 0; row < d; row++){
        for (int col = 0; col < d; col++){

            // determine pos of blank tile
            if (board[row][col] == 0){
                blankrow = row;
                blankcol = col;

            // determine if blank tile is out of bounds
            if (blankrow + 1 > d-1 || blankcol + 1 > d-1 || blankrow -1 > d-1 || blankcol - 1 > d-1){
                return false;
                }
            }

            // determine pos of user tile
            if (board[row][col] == tile) {
                tilerow = row;
                tilecol = col;
            // determine if tile move is out of bounds
                if (tilerow + 1 > d-1 || tilecol + 1 > d-1 || tilerow - 1 > d-1 || tilecol - 1 > d-1){
                    return false;
                }

                else if ((tilerow == blankrow) && (tilecol == blankcol +1 || tilecol == blankcol-1)) || ((tilecol == blankcol) && (tilerow == blankcol +1 || tilerow == blankcol-1)){
                // legal move is permitted...blankrow and col must be updated once swap takes places
                temp = board[row][col];
                board[row][col] = tile;
                tile = temp;
                    return true;
                }

            }

            }


    }
}