Number of Islands

You are given a 2D matrix consisting of the following:
1: land
0: water
Considering N-8 neighbourhood, your task is to find the number of islands in the given landscape.
Assume that the the 2D matrix is surrounded by water beyond the boundaries.

Definitions:
N-8 neighbourhood: 2 cells are considered neighbours, if they share an edge or a corner.
Island: A piece of connected land surrounded by water.

Input Format

First line of input contains T – number of test cases. The first line of each test case contains R, C – the size of the matrix. Its followed by a matrix of size RxC, consisting only of 0s and 1s.

Constraints

1 <= T <= 100
1 <= R,C <= 500

Output Format

For each test case, print the total number of islands, separated by new line.

Input	Output
3 4 8 01001101 10001010 00100100 01101101 6 1 0 1 0 0 1 1 9 5 00000 10001 00110 01100 10000 00000 00101 00011 00110	4 2 3

import java.util.Scanner;

public class Main {

    public static int Solution(char[][] array){
        int result = 0;

        for(int i=0; i<array.length; ++i){
            for(int j=0; j<array[0].length; ++j){
                if(array[i][j] == '1'){
                    dfs(array, i, j);
                    ++result;
                }
            }
        }

        return result;
    }

    public static void dfs(char[][] island, int i, int j){
        if(i<0 || i>=island.length || j<0 || j>=island[0].length)
            return;

        if(island[i][j] != '1')
            return;

        island[i][j] = '2';

        // Checking all the 8 directions..
        dfs(island, i-1, j-1);
        dfs(island, i-1, j);
        dfs(island, i-1, j+1);
        dfs(island, i, j-1);
        dfs(island, i, j+1);
        dfs(island, i+1, j-1);
        dfs(island, i+1, j);
        dfs(island, i+1, j+1);
    }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int test_cases = sc.nextInt();

        while(test_cases-->0){
            int rows = sc.nextInt();
            int columns = sc.nextInt();

            char[][] matrix = new char[rows][columns];

            for(int i=0; i<matrix.length; i++){
                String input = sc.next();
                for(int j=0; j<matrix[0].length; j++){
                    matrix[i][j] = input.charAt(j);
                }
            }
            int values = Solution(matrix);
            System.out.println(values);
        }
    }
}