419
class Solution {
public:
int countBattleships(vector<vector<char>>& board) {
if (board.empty() || board[0].empty()) return 0;
int res = 0, m = board.size(), n = board[0].size();
for (int i = 0; i < m; ++i) {
for (int j = 0; j < n; ++j) {
if (board[i][j] == 'X' && (i == 0 || board[i - 1][j] != 'X') && (j == 0 || board[i][j - 1] != 'X')) ++res;
}
}
return res;
}
};
//找起始点，上方和左方不可以为‘X’