[PS][java][완전탐색][BFS]/[탈출]

boj-java-3055.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class Main {
    static int r,c;
    static int[][] map;
    static boolean[][] visit;
    static Queue<Point> water, kak;
    static Point start,dest;
    static class Point{
        int r,c;
        Point(int r, int c){
            this.r = r;
            this.c = c;
        }
    }
    static int[] dx = {0,0,1,-1};
    static int[] dy = {1,-1,0,0};
    static void waterMove(){
        int size = water.size();
        for(int i=0; i< size; i++){
            Point curr = water.poll();
            for(int k=0; k<4; k++){
                int nx = curr.r + dx[k];
                int ny = curr.c + dy[k];
                if(nx<0 || r<= nx || ny <0 || c<=ny) continue;
                if(visit[nx][ny]) continue;
                if(nx==dest.r && ny ==dest.c) continue;
                if(map[nx][ny] == -1) continue;
                map[nx][ny] = -1;
                water.offer(new Point(nx,ny));
            }
        }
    }
    static void bfs(Point start){
        visit[start.r][start.c] = true;
        kak.offer(start);
        while(!kak.isEmpty()){
            waterMove();
            int size = kak.size();
            for(int i=0; i<size; i++){
                Point curr = kak.poll();
                for(int k=0; k<4; k++){
                    int nx = curr.r + dx[k];
                    int ny = curr.c + dy[k];
                    if(nx<0 || r<= nx || ny <0 || c<=ny) continue;
                    if(visit[nx][ny]) continue;
                    if(map[nx][ny]==-1) continue;
                    visit[nx][ny] = true;
                    map[nx][ny] = map[curr.r][curr.c] + 1;
                    kak.offer(new Point(nx,ny));
                    if(nx==dest.r && ny ==dest.c) break;
                }
            }
        }
    }

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] rc = br.readLine().split(" ");
        r = Integer.parseInt(rc[0]);
        c = Integer.parseInt(rc[1]);
        map = new int[r][c];
        visit = new boolean[r][c];
        water = new LinkedList<>();
        kak = new LinkedList<>();
        for(int i=0; i< r; i++){
            String line = br.readLine();
            for(int j=0; j<c; j++){
                switch(line.charAt(j)){
                    case '.':
                        map[i][j] = 0;
                        break;
                    case '*':
                        map[i][j] = -1;
                        water.offer(new Point(i,j));
                        break;
                    case 'S':
                        start = new Point(i,j);
                        break;
                    case 'D':
                        dest = new Point(i,j);
                        break;
                    case 'X':
                        map[i][j] = -1;
                        break;
                    default :
                        System.out.println("default");
                }
            }
        }
        bfs(start);

        if(map[dest.r][dest.c] != 0){
            System.out.println(map[dest.r][dest.c]);
        }else{
            System.out.println("KAKTUS");
        }
    }
}