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Recursion-maze problem - Rat in the Maze - Game

 



package com.bei.Demo01_recursion;


public class MiGong {
    public static void main(String[] args) 
{
        //First create a two-dimensional array to simulate the maze

        int [][]map=new int[8][7];
        //Use 1 for wall
        for (int i = 0; i <7 ; i++) {
            map[0][i]=1;
            map[7][i]=1;
        }
        for (int i = 0; i <8 ; i++) {
            map[i][0]=1;
            map[i][6]=1;
        }
        //Set the bezel
        map[3][1]=1;
        map[3][2]=1;
        //Output
        for (int i = 0; i <8 ; i++) {
            for (int j = 0; j < 7; j++) {
                System.out.print(map[i][j]+" ");
            }
            System.out.println();
        }
        System.out.println("----------------------------");
        setWay(map,1,1);
        for (int i = 0; i <8 ; i++) {
            for (int j = 0; j < 7; j++) {
                System.out.print(map[i][j]+" ");
            }
            System.out.println();
        }
    }
    //Use recursive backtracking to find the way to the ball
    //1.mapRepresents the map
    //2.i,j Indicates starting from that location on the map (1,1)
    //2.If you can get to the location of map[6][5], then you can go
    //4Convention: When map[i][j]=0, it means that it has not been found. 1 means that the wall 2 means that the path can be taken. 3 means that the point has been passed but cannot be passed.

    //5.Strategy: Down-Right-Up-Left, if the point cannot be reached, backtrack
    public static boolean setWay(int [][]map,int i,int j){
        if(map[6][5]==2){
            return true;
        }else{
            if(map[i][j]==0){
                map[i][j]=2;
                if(setWay(map,i+1,j)){
                    return true;
                }else if(setWay(map,i,j+1)){
                    return true;
                }else if(setWay(map,i-1,j)){
                    return true;
                }else if(setWay(map,i,j-1)){
                    return true;
                }else {
                    map[i][j]=3;
                    return false;
                }
            }else {
                return false;
            }
        }
    }
}

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