[JAVA] 백준 1012 유기농배추

import java.util.*;

public class Main {

static int T;

static int M;

static int N;

static int K;

static int[][] map;

static boolean[][] visit;

static int[] dx = {0,1,0,-1};

static int[] dy = {1,0,-1,0};

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

T = sc.nextInt();

for(int i=0;i<T;i++){

int cnt =0;

M = sc.nextInt();

N = sc.nextInt();

K = sc.nextInt();

map = new int[N][M];

visit = new boolean[N][M];

for(int j=0;j<K;j++){

int x = sc.nextInt();

int y = sc.nextInt();

map[y][x] = 1;

}

for(int j=0;j<N;j++){

for(int k=0;k<M;k++){

if(map[j][k]==1 && visit[j][k]==false){

dfs(j,k);

cnt++;

}

}

}

System.out.println(cnt);

}

}

public static void dfs(int yy, int xx){

visit[yy][xx]=true;

for(int i=0;i<4;i++){

int new_y = yy + dy[i];

int new_x = xx + dx[i];

if(new_y>=0 && new_x>=0 && new_y<N && new_x<M){

if(map[new_y][new_x]==1 && visit[new_y][new_x]==false){

dfs(new_y,new_x);

}

}

}

}

}