gistfile1.txt

using System;

class Solution
{
    public static int GetNumberOfIslands(int[,] binaryMatrix)
    {
      // your code goes here
    }

    static void Main(string[] args)
    {

    }
}

/*
keywords: 2D array, 0 and 1, 
same row, same column , at most 4 neighbors, not 8 ones


010020
010300

ask: return number of islands

                         [0,    A,    0,    B,    0],
                         [0,    0,    -1,    -1,    -1],
                         [E,    0,    0,    -1,    0],
                         [0,    C,    -1,    0,    0],
                         [D,    0,    -1,    0,    E] 
 BFS - value 1, mark visited -1
 it is in the range of matrix and also it is 1, and then add to queue

your appear.in is laggy. maybe turn off the video to conserve bandwidth?

time: O(rows*columns)
queue: at most 16 ->   O(m*n) - you are correct 
rows * columns  -> 1 -> 


Follow-up 1:
Let's say the dataset is very large.
The input data is now a list of coordinates for any piece of land.
No guarantee on order of coordinates given to you.  (random order)

size k -> preprocessing size k -> order by sort by row, second col
put all cordination into dictionary to loop up O(1) <- 
key = row + ';' + col -> 1 -> value 1's dictionary -> O(1)
visited one -> look up hashset O(1)
(1000, 23)
(0, 1)
(0, 3)
(3948, 1837)

1st loop:  insert all into land_dictionary
2nd loop:  lookup neighbors in land_dcitionary and mark in visisted dictionary

returning number of island at the very end

Follow-up 2:
We have the same conditions as above.  

  0123
0 0bec
1 000d
2 a000

Stream:
a: (2, 0)
b: (0, 1)
c: (0, 3)
d: (1, 3)
e: (0, 2)

0bec
000d
a000

Return:
a, b, c, d, e
1, 2, 3, 3, 2

Result:
[1, 2, 2, 3]

1. find island, assign id,using global id startin from 1 , increment one at time
2. still want to go over the steam one by one, mark element, create -> save steamid, id -> dictionary
3. go over stream, look up dictionary, try to find island 
*/