419. Battleships in a Board

class Solution(object):
    def countBattleships(self, board):
        """
        :type board: List[List[str]]
        :rtype: int
        """
        if not board or len(board[0])==0: return 0
        
        count=1 if board[0][0]=='X' else 0
        
        for i in range(1,len(board)):
            if board[i][0]=='X' and board[i-1][0]=='.':
                count+=1
        for j in range(1,len(board[0])):
            if board[0][j]=='X' and board[0][j-1]=='.':
                count+=1
        for i in range(1,len(board)):
            for j in range(1,len(board[0])):
                if board[i][j]=='X' and board[i][j-1]=='.' \
                and board[i-1][j]=='.':
                    count+=1
        return count