(UVA) Counting Stars - Solution

I used Depth-First Search to solve this problem.


import java.io.*;
import java.util.*;

class Main {
    public static char[][] matrix;
    public static boolean[][] visited;
    public static int[] vx = {-1,-1,-1,0,0,1,1,1};
    public static int[] vy = {-1,0,1,-1,1,-1,0,1};
    public static int count;
    public static int row;
    public static int col;
   
    public static void dfs(int currX, int currY) {
        if (currX < 0 || currY < 0 || currX >= row || currY >= col || matrix[currX][currY] != '*' || visited[currX][currY]) {
            return;
        }
       
        count++;
        visited[currX][currY] = true;
        for (int i = 0; i < 8; i++) {
            int nextX = currX+vx[i];
            int nextY = currY+vy[i];
            dfs(nextX, nextY);
        }
    }
   
    public static void process() throws NumberFormatException, IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       
        String line = br.readLine();
        String[] s = line.split("\\s");
        row = Integer.parseInt(s[0]);
        col = Integer.parseInt(s[1]);
        while (row != 0 || col != 0) {
            matrix = new char[row][col];
            for (int i = 0; i < row; i++) {
                line = br.readLine();
                for (int j = 0; j < col; j++) {
                    matrix[i][j] = line.charAt(j);
                }
            }
               
            int countStars = 0;
            visited = new boolean[row][col];
            for (int i = 0; i < row; i++) {
                for (int j = 0; j < col; j++) {
                    count = 0;
                    dfs(i, j);
                    if (count == 1) {
                        countStars++;                           
                    }
                }
            }
       
            System.out.println(countStars);
           
            line = br.readLine();
            s = line.split("\\s");
            row = Integer.parseInt(s[0]);
            col = Integer.parseInt(s[1]);
        }      
                                             
        return;
    }
   
    public static void main(String[] args) throws NumberFormatException, IOException {
        Main m = new Main();
        m.process();
       
        System.exit(0);
    }
}