白駿4963島の個数

トラブルシューティング

ソースコード

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;
import java.util.StringTokenizer;

public class Main {
    static int w; // 열
    static int h; // 행
    static int[][] map;
    static boolean[][] check;
    // 상하좌우 대각선
    static int[] dx = {-1, -1, -1, 0, 1, 1, 1, 0};
    static int[] dy = {-1, 0, 1, 1, 1, 0, -1, -1};
    static int count;
    static Queue<Node> queue;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            w = Integer.parseInt(st.nextToken());
            h = Integer.parseInt(st.nextToken());
            count = 0;
            if (w == 0 && h == 0) {
                break;
            }
            map = new int[h][w];
            check = new boolean[h][w];
            for (int i = 0; i < h; i++) {
                st = new StringTokenizer(br.readLine());
                for (int j = 0; j < w; j++) {
                    map[i][j] = Integer.parseInt(st.nextToken());
                }
            }
            for (int i = 0; i < h; i++) {
                for (int j = 0; j < w; j++) {
                    if (map[i][j] == 1 && !check[i][j]) {
                        bfs(i, j);
                        count++;
                    }
                }
            }
            System.out.println(count);
        }
    }

    public static void bfs(int x, int y) {
        queue = new LinkedList<>();
        queue.add(new Node(x, y));
        check[x][y] = true;
        while (!queue.isEmpty()) {
            Node node = queue.poll();
            for (int i = 0; i < 8; i++) {
                int nx = node.x + dx[i];
                int ny = node.y + dy[i];
                if (nx >= 0 && ny >= 0 && nx < h && ny < w) {
                    if (map[nx][ny] == 1 && !check[nx][ny]) {
                        queue.add(new Node(nx, ny));
                        check[nx][ny] = true;
                    }
                }
            }
        }
    }
}

class Node {
    int x;
    int y;

    public Node(int x, int y) {
        this.x = x;
        this.y = y;
    }
}