백준1012_유기농배추

 

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import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
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public class BOJ1012_유기농배추_최성호 {
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    static int[][] map;
    static boolean[][] visited;
    static int[] dx = { 0, 0, 1, -1 };
    static int[] dy = { 1, -1, 0, 0 };
    static int m;
    static int n;
    static Queue<Integer> q;
​
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
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        int tc = sc.nextInt();
        for (int i = 1; i <= tc; i++) {
            int cnt = 0;
            m = sc.nextInt(); // 가로
            n = sc.nextInt(); // 세로
            int k = sc.nextInt(); // 배추위치 개수
            map = new int[m][n];
            visited = new boolean[m][n];
            for (int j = 0; j < k; j++) {
                int x = sc.nextInt();
                int y = sc.nextInt();
                map[x][y] = 1;
            }
            for (int j = 0; j < m; j++) {
                for (int k1 = 0; k1 < n; k1++) {
                    if (map[j][k1] == 1 && !visited[j][k1]) {
                        bfs(j, k1);
                        //dfs(j, k1);
                        cnt++;
                    }
                }
            }
            System.out.println(cnt);
        } // end of tc
    } // end of main
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    // DFS로
    private static void dfs(int x, int y) {
        visited[x][y] = true;
        for (int i = 0; i < 4; i++) {
            int nx = x + dx[i];
            int ny = y + dy[i];
            if(nx >= 0 && nx < m && ny >= 0 && ny < n) {
                if(map[nx][ny] == 1 && !visited[nx][ny]) {
                    dfs(nx, ny);
                }
            }
        }
    } // end of dfs
​
    // BFS로
    private static void bfs(int x, int y) {
        q = new LinkedList<Integer>();
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        visited[x][y] = true;
        q.add(x);
        q.add(y);
​
        while (!q.isEmpty()) {
            int nx = q.poll();
            int ny = q.poll();
            for (int i = 0; i < 4; i++) {
                nx += dx[i];
                ny += dy[i];
                if (nx >= 0 && nx < m && ny >= 0 && ny < n) {
                    if (map[nx][ny] == 1 && !visited[nx][ny]) {
                        q.add(nx);
                        q.add(ny);
                        visited[nx][ny] = true;
                    }
                }
            }
        }
    } // end of bfs
} // end of class
​