인프런 커뮤니티 질문&답변

아래와 같이 작성했는데, 답이 0이 나옵니다.
잘못된 부분이 있을까요??

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


class Main {
	public static int n,m,L;
	public static int[][] map ,dist;
	public static boolean[][] visit;
	public static int[] dx = {0,0,1,-1};
	public static int[] dy = {1,-1,0,0};
	public int solution(int[][] board){
		int answer = 0;
		n=board.length;
		m=board[0].length;
		
		map = new int[n][m];
		dist = new int[n][m];
		visit = new boolean[n][m];
		L=0;
		for(int i=0; i<n;i++) {
			for(int j=0; j<m; j++) {
				map[i][j] = board[i][j];
			}
		}
		
		bfs(0,0);
		return answer;
	}
	public static int bfs(int r,int c) {
		Queue<int[]> q =new LinkedList<>();
		q.offer(new int[] {r,c}); //0,0대입
		visit[r][c] = true;
		
		while(!q.isEmpty()) {
			L++;
			int len = q.size();
			
			for(int i=0; i<len; i++) {
				int[] tmp = q.poll();
				int nowx = tmp[0];
				int nowy = tmp[1];
				
				for(int j=0;j<4;j++) { //상하좌우 탐색
					
					int nx = nowx+dx[j];
					int ny = nowy+dy[j];
					
					if(nx>=0 && ny>=0 && nx<n && ny<m) { //맵 범위안이고
						if(!visit[nx][ny] && map[nx][ny]==0) { //다음 노드가 방문안햇고, 방문할 수 있다
							dist[nx][ny]=L;
							q.offer(new int[] {nx,ny});
							visit[nx][ny] = true;
						}
					}
				}
			}
		}
		return dist[n-1][m-1];
	}
	public static void main(String[] args){
		Main T = new Main();
		int[][] arr={{0, 0, 0, 0, 0, 0, 0}, 
			{0, 1, 1, 1, 1, 1, 0}, 
			{0, 0, 0, 1, 0, 0, 0}, 
			{1, 1, 0, 1, 0, 1, 1}, 
			{1, 1, 0, 1, 0, 0, 0}, 
			{1, 0, 0, 0, 1, 0, 0}, 
			{1, 0, 1, 0, 0, 0, 0}};
		System.out.println(T.solution(arr));
	}
}