Suppose ship's head is on left or top side.

Traverse left to right, top to down.

Increment total number if we find the head.

```
int countBattleships(vector<vector<char>>& board) {
int size = board.size();
int csize = size > 0 ? board[0].size() : 0;
int count = 0;
for (int i = 0; i < size; i++) {
for (int j = 0; j < csize; j++) {
if (board[i][j] == 'X' && !(i > 0 && board[i - 1][j] == 'X' || j > 0 && board[i][j - 1] == 'X')) {
count++;
}
}
}
return count;
}
```