# 419. Battleships in a Board

## Problem

Given an m x n matrix board where each cell is a battleship ‘X’ or empty ‘.’, return the number of the **battleships** on board.

**Battleships** can only be placed horizontally or vertically on board. In other words, they can only be made of the shape 1 x k (1 row, k columns) or k x 1 (k rows, 1 column), where k can be of any size. At least one horizontal or vertical cell separates between two battleships (i.e., there are no adjacent battleships).

Example 1:

```
Input: board = [["X",".",".","X"],[".",".",".","X"],[".",".",".","X"]]
Output: 2
```

Example 2:

```
Input: board = [["."]]
Output: 0
```

## Code

```
class Solution {
public int countBattleships(char[][] board) {
int count = 0;
for(int i = 0; i < board.length; i++) {
for(int j = 0; j < board[0].length; j++) {
char c = board[i][j];
if(c == 'X') {
if(i >= 1 && board[i - 1][j] == 'X') continue;
if(j >= 1 && board[i][j - 1] == 'X') continue;
count++;
}
}
}
return count;
}
}
```

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421. Maximum XOR of Two Numbers in an Array