青训营后端编程题2—DFS解法

import java.io.InputStream;
import java.util.Scanner;

/**
 * @Author WHJ
 * @Date 27/12/2022 11:01
 * @Version 1.0 （版本号）
 * @Description:
 */
public class GraphAlgo {
    public int[][] map;
    public int row;
    public int column;
    int[][] visited;
    int max;
    int count;
    public GraphAlgo(int row, int column) {
        this.row = row;
        this.column = column;
        this.map=new int[row][column];
        this.visited=new int[row][column];
        max=0;
        count=0;
        for(int i=0;i<row;i++){
            for (int j=0;j<column;j++){
                visited[i][j]=0;
            }
        }
    }

    void DepthFirstSearch(int x,int y){
        if(map[x][y]==1||visited[x][y]==1) return;
        //访问这个点
        this.count++;
        this.visited[x][y]=1;
        //继续深度探索
        if(x+1<this.row){
            DepthFirstSearch(x+1,y);
        }
        if(x-1>=0){
            DepthFirstSearch(x-1,y);
        }
        if(y+1<this.column){
          DepthFirstSearch(x,y+1);
        }
        if(y-1>=0){
           DepthFirstSearch(x,y-1);
        }
        return;
    }
    void showGraph(){
        for (int i = 0; i < row; i++) {
            for (int j = 0; j < column; j++) {
                System.out.print(map[i][j]+" ");
            }
            System.out.println("//");
        }
    }
    void findMaxConnectedsub(){
           for(int i=0;i<this.row;i++){
               for (int j = 0; j < this.column; j++) {
                   if(map[i][j]==1||visited[i][j]==1){
                       continue;
                   }
                   else{
                       this.count=0;
                       DepthFirstSearch(i,j);
                       if(this.count>this.max){
                           this.max=this.count;
                       }
                   }
               }
           }
    }

    public static void main(String[] args) {
        Scanner is=new Scanner(System.in);
        System.out.println("输入图的行");
        int m=is.nextInt();
        System.out.println("输入图的列");
        int n=is.nextInt();
        GraphAlgo graphAlgo=new GraphAlgo(m,n);
        System.out.println("输入图");
        for(int i=0;i<graphAlgo.row;i++){
            for (int j = 0; j < graphAlgo.column; j++) {
                graphAlgo.map[i][j]=is.nextInt();
            }
        }
        graphAlgo.findMaxConnectedsub();
        System.out.println("最大推荐数："+graphAlgo.max);
    }
}