迷宫问题 回溯

package huan._迷宫问题;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;


public class Main {
    //方向
    static int[][] direction = new int[][]{{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
    static int[][] mark; //记录已经访问
    static List<int[]> list; //存储结果集

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()){
            list = new ArrayList<>();

            int m = in.nextInt();
            int n = in.nextInt();
            mark = new int[m][n];
            int[][] grid = new int[m][n];
            for (int i = 0; i < m; i++) {
                for (int j = 0; j < n; j++) {
                    grid[i][j] = in.nextInt();
                }
            }
            dfs(grid, 0, 0);
        }

    }

    public static boolean dfs(int[][] grid, int i, int j) {
        if (i == grid.length - 1 && j == grid[0].length - 1) {
            //当到达终点时 输出
            list.add(new int[]{i,j});
            for (int t = 0; t < list.size(); t++) {
                System.out.println("("+list.get(t)[0]+","+list.get(t)[1]+")");
            }
            return true;
        }
        if (i<0||i>=grid.length||j<0||j>=grid[0].length||mark[i][j]==1) return false;
        if(grid[i][j]==1)return false;

        //添加
        mark[i][j]=1;
        list.add(new int[]{i, j});

        //做选择
        for (int k = 0; k < 4; k++) {
            int row = i + direction[k][0];
            int col = j + direction[k][1];
            if (dfs(grid, row, col)){
                //如果到达终点 就直接返回 
                return true;
            }
        }

        //删除
        mark[i][j]=0;
        list.remove(list.size()-1);
        return false;
    }


}