BattleShipInBoard.java

//Given an 2D board, count how many battleships are in it. The battleships are represented with 'X's, empty slots are represented with '.'s. You may assume the following rules:
//        You receive a valid board, made of only battleships or empty slots.
//        Battleships can only be placed horizontally or vertically. In other words, they can only be made of the shape 1xN (1 row, N columns) or Nx1 (N rows, 1 column), where N can be of any size.
//        At least one horizontal or vertical cell separates between two battleships - there are no adjacent battleships.
//Example:
//        X..X
//        ...X
//        ...X
//    Ans=2
//Example:
//        ...X
//        XXXX
//        ...X
//        This is an invalid board that you will not receive - as battleships will always have a cell separating between them.
public class BattleShipInBoard {
    public int countBattleships(char[][] board) {

        int count=0;


        for(int i=0;i<board.length;i++)
        {
            for(int j=0;j<board[i].length;j++)
            {
                if(board[i][j]=='X')
                {
                    char lookedDown=lookAhead(i+1,j,board);
                    char lookedNext=lookAhead(i,j+1,board);
                    if(lookedDown!='X')
                    {
                        if(lookedNext=='.' || lookedNext=='n')
                        {
                            count++;
                        }
                    }
                }

            }
        }


        return count;
    }

    private char lookAhead(int i,int j,char[][] arr){
        try{
            return arr[i][j];
        }catch (Exception e){
            return 'n';
        }
    }
}