Java Exercises: Read the mass data and find the number of islands
Java Basic: Exercise-237 with Solution
There are 10 vertical and horizontal squares on a plane. Each square is painted blue and green. Blue represents the sea, and green represents the land. When two green squares are in contact with the top and bottom, or right and left, they are said to be ground. The area created by only one green square is called "island". For example, there are five islands in the figure below.
Write a Java program to read the mass data and find the number of islands.
Input:
A single data set is represented by 10 rows of 10 numbers representing green squares as 1 and blue squares as zeros.
Output: For each data set, output the number of islands.
Pictorial Presentation:
Sample Solution:
Java Code:
import java.util.Scanner;
public class test {
public static boolean[][] map;
public static int[][] move = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
public static void fds(int i, int j){
map[i][j] = false;
for(int k=0;k<4;k++){
int i2 = i+move[k][0];
int j2 = j+move[k][1];
if(0<=i2&&i2<10&&0<=j2&&j2<10&&map[i2][j2])fds(i2,j2);
}
}
public static void main(String[] args) {
System.out.println("Input 10 rows of 10 numbers representing green squares (island) as 1 and blue squares (sea) as zeros");
Scanner sc = new Scanner(System.in);
map = new boolean[10][10];
for(int i=0;i<10;i++){
char[] s = sc.next().toCharArray();
for(int j=0;j<10;j++){
map[i][j] = s[j]=='1';
}
}
int x = 0;
for(int i=0;i<10;i++){
for(int j=0;j<10;j++){
if(map[i][j]){
fds(i, j);
x++;
}
}
}
System.out.println("Number of islands:");
System.out.println(x);
}
}
Sample Output:
Input 10 rows of 10 numbers representing green squares (island) as 1 and blue squares (sea) as zeros 1100000111 1000000111 0000000111 0010001000 0000011100 0000111110 0001111111 1000111110 1100011100 1110001000 Number of islands: 5
Flowchart:
Java Code Editor:
Contribute your code and comments through Disqus.
Previous: Write a Java program to sum of all numerical values (positive integers) embedded in a sentence.
Next: Write a Java program to restore the original string by entering the compressed string with this rule.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
Java: Tips of the Day
How to sort an ArrayList?
Collections.sort(testList); Collections.reverse(testList);
That will do what you want. Remember to import Collections though!
Ref: https://bit.ly/32urdSe
- New Content published on w3resource:
- HTML-CSS Practical: Exercises, Practice, Solution
- Java Regular Expression: Exercises, Practice, Solution
- Scala Programming Exercises, Practice, Solution
- Python Itertools exercises
- Python Numpy exercises
- Python GeoPy Package exercises
- Python Pandas exercises
- Python nltk exercises
- Python BeautifulSoup exercises
- Form Template
- Composer - PHP Package Manager
- PHPUnit - PHP Testing
- Laravel - PHP Framework
- Angular - JavaScript Framework
- Vue - JavaScript Framework
- Jest - JavaScript Testing Framework