Package g0101_0200.s0200_number_of_islands

Class Solution

java.lang.Object
g0101_0200.s0200_number_of_islands.Solution
public class Solution extends java.lang.Object
200 - Number of Islands.

Medium

Given an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islands.

An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water.

Example 1:

Input:

 grid = [
   ["1","1","1","1","0"],
   ["1","1","0","1","0"],
   ["1","1","0","0","0"],
   ["0","0","0","0","0"]
 ]

Output: 1

Example 2:

Input:

 grid = [
   ["1","1","0","0","0"],
   ["1","1","0","0","0"],
   ["0","0","1","0","0"],
   ["0","0","0","1","1"]
 ]

Output: 3

Constraints:

  • m == grid.length
  • n == grid[i].length
  • 1 <= m, n <= 300
  • grid[i][j] is '0' or '1'.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    numIslands(char[][] grid)
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • numIslands

      public int numIslands(char[][] grid)