Figure bfs_maze

Figure bfs_maze

/*
…11111111111111111111111111111
11.111111…1111111111.1111
11.111111…111.11111111…1111
11.11111111111.1111111111.111111
11.111111…111111
11.111111.11111111111.11111.1111
11.111111.11111111111.11111…111
11…111111111.11111.1111
11111.111111111111111.11…1111
11111.111111111111111.11.11.1111
11111.111111111111111.11.11.1111
111…111111111111111.11.11.1111
111.11111111111111111…11.1111
111.11111111111111111111111.1111
111.1111.111111111111111…11
111.1111…111111111.1111.11
111.1111.11111.111111111.1111.11
111…11111.111111111.1111111
11111111111111.111111111.111…1
11111111111111…1.1
111111111111111111111111111111…

As shown in the picture above, the entrance and exit of the maze are respectively: the upper left corner and the lower right corner
"1" is the wall, "." is the pathway.
How many steps do you need to take to find the shortest?

• */

import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;


public class 图的bfs_迷宫 {
    
    
  public static void main(String[] args) {
    
    
    Scanner scanner = new Scanner(System.in);
    int m = 21;
    int n = 32;
    char[][] graph = new char[m][n];
    int[][] vis = new int[m][n];//标记哪些点已经被访问
    Queue<Node> queue = new LinkedList<>();
    for (int i = 0; i < m; i++) {
    
    
      graph[i] = scanner.nextLine().toCharArray();
    }
    // for (int j = 0; j < graph.length; j++) {
    
    
    //   for (int k = 0; k < graph[j].length; k++) {
    
    
    //     System.out.print(graph[j][k]);
    //   }
    //   System.out.println();
    // }

    Node start = new Node(0, 0, 0);
    queue.add(start);
    while (!queue.isEmpty()) {
    
    
      Node poll = queue.poll();
      int x = poll.x;
      int y = poll.y;
      int deep = poll.depth;
      vis[x][y] = 1;//标注为已访问
      //判断是否到达终点
      if (x == m - 1 && y == n - 1) {
    
    //走到出口
        System.out.println(poll.depth);
        break;
      }
      //  加四个邻居
      if (x - 1 >= 0 && vis[x - 1][y] == 0 && graph[x - 1][y] == '.') {
    
    
        queue.add(new Node(x - 1, y, deep + 1));
      }
      if (x + 1 < m && vis[x + 1][y] == 0 && graph[x + 1][y] == '.') {
    
    
        queue.add(new Node(x + 1, y, deep + 1));
      }
      if (y - 1 >= 0 && vis[x][y - 1] == 0 && graph[x][y - 1] == '.') {
    
    
        queue.add(new Node(x, y - 1, deep + 1));
      }
      if (y + 1 < n && vis[x][y + 1] == 0 && graph[x][y + 1] == '.') {
    
    
        queue.add(new Node(x, y + 1, deep + 1));
      }
    }
  }

  static class Node {
    
    
    int x;
    int y;
    int depth;

    public Node(int x, int y, int depth) {
    
    
      this.x = x;
      this.y = y;
      this.depth = depth;
    }
  }
}