[BOJ]7569번 : 토마토

https://www.acmicpc.net/problem/7569

7569번: 토마토

 

분류 : BFS

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

class MyScanner {
    BufferedReader br;
    StringTokenizer st;

    public MyScanner() {
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    String next() {
        while (st == null || !st.hasMoreElements()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }

    int nextInt() {
        return Integer.parseInt(next());
    }

    long nextLong() {
        return Long.parseLong(next());
    }

    double nextDouble() {
        return Double.parseDouble(next());
    }

    char nextChar() {
        return next().charAt(0);
    }
}

public class Main
{
    public static PrintWriter out;
    static int R,C,H;
    static boolean[][][] visited;
    static int[][][] farm;
    static int[] dx = {0,0,0,0,-1,1};
    static int[] dy = {0,0,-1,1,0,0};
    static int[] dz = {-1,1,0,0,0,0};
    static Queue<Point> q = new LinkedList<Point>();
    public static void main(String[] args) throws IOException
    {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));
        R = sc.nextInt();
        C = sc.nextInt();
        H = sc.nextInt();
        farm= new int[H][C][R];
        visited = new boolean[H][C][R];
        for(int h=0;h<H;h++)
        {
            for(int c =0;c<C;c++)
            {
                for(int r=0;r<R;r++)
                {
                    farm[h][c][r]=sc.nextInt();
                    if(farm[h][c][r]==1)
                    {
                        q.offer(new Point(h,c,r));
                    }
                }
            }
        }
        bfs();
        boolean check =true;
        int max =-1;
        loop1: for(int h=0;h<H;h++)
        {
            for(int c =0;c<C;c++)
            {
                for(int r=0;r<R;r++)
                {
                    max = Math.max(max, farm[h][c][r]);
                    if(farm[h][c][r]==0){
                        check = false;
                        break loop1;
                    }
                }
            }
        }
        
        if(!check){
            out.println(-1);
        }
        else{
            out.print(max-1);
        }
        out.flush();
    }
    private static void bfs() {
        
        while(!q.isEmpty())
        {
            int size =q.size();
            for(int sz =0; sz<size;sz++)
            {
                Point p = q.poll();
                int h = p.h;
                int c = p.c;
                int r = p.r;
                for(int dr = 0;dr<6;dr++)
                {
                    int ch = h+dz[dr];
                    int cr = r+dx[dr];
                    int cc = c+dy[dr];
                    if(ch>=0 && cr>=0 && cc>=0 && cr<R && cc<C && ch<H)
                    if(farm[ch][cc][cr]==0 && visited[ch][cc][cr]==false){
                        farm[ch][cc][cr]=farm[h][c][r]+1;
                        visited[ch][cc][cr] = true;
                        q.offer(new Point(ch,cc,cr));
                    }                    
                }
            }
        }
    }
}
class Point{
    int h;
    int c;
    int r;    
    Point(int h,int c , int r){
        this.h=h;
        this.c=c;
        this.r=r;
    }
}

https://www.acmicpc.net/problem/7576 -> 토마토 문제와 비슷하지만 층 개념이 생겼다는 점이 다르다.

그래서 for문을 돌릴 때 높이 -> 세로 -> 가로 식으로 진행되는 것만 조심하면 되지 않을까 싶다.