Package g0401_0500.s0419_battleships_in_a_board

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    419 - Battleships in a Board\.

    Medium

    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

    Constraints:

    • m == board.length

    • n == board[i].length

    • 1 <= m, n <= 200

    • board[i][j] is either '.' or 'X'.

    Follow up: Could you do it in one-pass, using only O(1) extra memory and without modifying the values board?

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Integer countBattleships(Array<CharArray> board)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait