#+ANKI_DECK: study_deck_02
* TODO 0200. Number of Islands :medium:
:PROPERTIES:
:NEETCODE: [[file:../../roadmap.org::*0200. Number of Islands][0200. Number of Islands]]
:END:

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:*


#+begin_src
Input: grid = [
  ["1","1","1","1","0"],
  ["1","1","0","1","0"],
  ["1","1","0","0","0"],
  ["0","0","0","0","0"]
]
Output: 1
#+end_src


*Example 2:*


#+begin_src
Input: grid = [
  ["1","1","0","0","0"],
  ["1","1","0","0","0"],
  ["0","0","1","0","0"],
  ["0","0","0","1","1"]
]
Output: 3
#+end_src


*Constraints:*

 - ~m == grid.length~

 - ~n == grid[i].length~

 - ~1 <= m, n <= 300~

 - ~grid[i][j]~ is ~'0'~ or ~'1'~.

** TODO Approach
Write your approach here.

** TODO Python
#+begin_src python :lc-problem 200 :lc-lang python3
class Solution:
    def numIslands(self, grid: List[List[str]]) -> int:
#+end_src

** TODO C++
#+begin_src cpp :lc-problem 200
class Solution {
public:
    int numIslands(vector<vector<char>>& grid) {
        
    }
};
#+end_src