题目：

题解：

func countBattleships(board [][]byte) (ans int) {
    for i, row := range board {
        for j, ch := range row {
            if ch == 'X' && !(i > 0 && board[i-1][j] == 'X' || j > 0 && board[i][j-1] == 'X') {
                ans++
            }
        }
    }
    return
}