Java版的广度优先寻路（BFS+并查集思想）

Posted 2022-12-19 z2529827226

import java.util.Deque;
import java.util.LinkedList;


class node
    int x;
    int y;


class Solution
    private int dir[][]=new int[][] 0,-1,-1,0,0,1,1,0;
    private node parentx[][];
    private int Count[][];
    private boolean used[][];
    private node start=new node();
    private node end=new node();
    private Deque<node> queue=new LinkedList<node>();
    private node temp;
    private boolean flag=false;
    public boolean isCheckMove(String[] map,node start) 
        return start.x>=0&&start.x<map.length&&start.y>=0&&start.y<map[start.x].length();
    
    public boolean printPath(String[] map) 
        while(parentx[temp.x][temp.y].x!=temp.x||parentx[temp.x][temp.y].y!=temp.y) 
            System.out.print(map[temp.x].charAt(temp.y)+"->");
            temp=parentx[temp.x][temp.y];         
        
        System.out.println(map[temp.x].charAt(temp.y));
        return true;
    
    public int dfs(String[] map,node start) 
        
        queue.offer(start);
        used[start.x][start.y]=true;
        Count[start.x][start.y]=1;
        
        while(!queue.isEmpty()) 
            start=queue.pop();
            for(int i=0;i<4;++i) 
                temp=new node();
                temp.x=start.x+dir[i][0];
                temp.y=start.y+dir[i][1];
                 if(temp.x==end.x&&temp.y==end.y) 
                     flag=true;
                     queue.addLast(temp);
                     parentx[temp.x][temp.y]=start;
                     Count[temp.x][temp.y]=Count[start.x][start.y]+1;
                     used[temp.x][temp.y]=true;
                    break;
                
                if(isCheckMove(map,temp)&&!used[temp.x][temp.y]) 
                     queue.addLast(temp);
                     parentx[temp.x][temp.y]=start;
                     Count[temp.x][temp.y]=Count[start.x][start.y]+1;
                     used[temp.x][temp.y]=true;
                
            
            if(flag) 
                break;
            
        
        return Count[temp.x][temp.y];
    
    
    public boolean nums(String map[]) 
        queue.clear();
        parentx=new node[map.length][map[0].length()];
        Count=new int[map.length][map[0].length()];
        used=new boolean[map.length][map[0].length()];
        for(int i=0;i<map.length;++i) 
            for(int j=0;j<map[i].length();++j) 
                used[i][j]=false;
                Count[i][j]=0;
                node tmp=new node();
                tmp.x=i;
                tmp.y=j;
                parentx[i][j]=tmp;
                if(map[i].charAt(j)==‘#‘) 
                    end.x=i;
                    end.y=j;
                
                if(map[i].charAt(j)==‘@‘) 
                    start.x=i;
                    start.y=j;
                
            
        
        System.out.println(dfs(map,start));
        printPath(map);
        return true;
    



public class First
     public static void main(String[] args) 
      Solution space = new Solution();
      String map[]= "****","@***","&&&&","&&&&","&#**";
      space.nums(map);
      for(String str:map) 
            System.out.println(str);