백준 7569

package baekjoon.DFS와BFS;

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 Main7569 {

   static int M, N, H;
   static int[][][] map, isVisited;
   static Queue<Point> q = new LinkedList<>();
   static int[] dz = {-1, 0, 0, 0, 0, 1};
   static int[] dy = {0, -1, 0, 1, 0, 0};
   static int[] dx = {0, 0, 1, 0, -1, 0};

   public static void main(String[] args) throws Exception {
      input();
      for (int i = 0; i < H; i++) {
         for (int j = 0; j < N; j++) {
            for (int k = 0; k < M; k++) {
               if (map[i][j][k] == 1) {
                  q.add(new Point(i, j, k));
                  isVisited[i][j][k]++;
               }
            }
         }
      }
      System.out.println(BFS());
   }

   private static int BFS() {
      int max = 0;
      while (!q.isEmpty()) {
         Point p = q.poll();
         for (int i = 0; i < 6; i++) {
            int nz = p.z + dz[i];
            int ny = p.y + dy[i];
            int nx = p.x + dx[i];
            if (isMap(nz, ny, nx))
               continue;
            q.add(new Point(nz, ny, nx));
            isVisited[nz][ny][nx] = isVisited[p.z][p.y][p.x] + 1;
            max = Math.max(max, isVisited[nz][ny][nx]);
         }
      }
      for (int i = 0; i < H; i++) {
         for (int j = 0; j < N; j++) {
            for (int k = 0; k < M; k++) {
               if (map[i][j][k] == 0 && isVisited[i][j][k] == -1) {
                  return -1;
               }
            }
         }
      }
      return max;
   }

   private static boolean isMap(int nz, int ny, int nx) {
      return nz < 0 || nz >= H || ny < 0 || ny >= N || nx < 0 || nx >= M || map[nz][ny][nx] != 0
         || isVisited[nz][ny][nx] > -1;
   }

   private static void input() throws IOException {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st = new StringTokenizer(br.readLine());
      M = Integer.parseInt(st.nextToken());
      N = Integer.parseInt(st.nextToken());
      H = Integer.parseInt(st.nextToken());
      map = new int[H][N][M];
      isVisited = new int[H][N][M];
      for (int i = 0; i < H; i++) {
         for (int j = 0; j < N; j++) {
            for (int k = 0; k < M; k++) {
               isVisited[i][j][k] = -1;
            }
         }
      }
      for (int i = H - 1; i >= 0; i--) {
         for (int j = 0; j < N; j++) {
            st = new StringTokenizer(br.readLine());
            for (int k = 0; k < M; k++) {
               map[i][j][k] = Integer.parseInt(st.nextToken());
            }
         }
      }
   }

   private static class Point {
      int z, y, x;

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