Solution (leetcode-in-java 1.23 API)

java.lang.Object
- g0101_0200.s0200_number_of_islands.Solution

```
public class Solution
extends 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
  
  All Methods Instance Methods Concrete Methods
  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 Detail
- Solution
```
public Solution()
```

Method Detail

numIslands

public int numIslands(char[][] grid)