Java: Stack Pop () не работает

Question

Я внедряю итеративный поиск DFS через матрицу через стек, чтобы сгенерировать лабиринт позже. Дело застряло, подталкивая первый элемент, даже не появляя его:

void DFS_I(int i, int j){ // receives starting position

     IJ aux = new IJ (i,j);

     int [][] movement = {{0,1},{1,0},{0,-1},{-1,0}};

     Stack <IJ> stack = new Stack();

     stack.push(aux);




     double random;
     while(!stack.empty()){

         IJ temp = (IJ)stack.peek();
         stack.pop(); 


         //random=(Math.random()*4);
         //System.out.println("stack size "+ stack.size());

        /* int index = 0;
         if ((random>=0)&&(random<1)) index = 1;
         else if((random >= 1) && (random < 2)) index = 2;
         else if (random>3) index = 3;
         int x = temp.i + movement[index][0];
         int y = temp.j + movement[index][1];
         while(x<0 || x>=M || y<0 || y>=N){
             random=(Math.random()*4);
             index = 0;
             if ((random>=0)&&(random<1)) index = 1;
             else if((random >= 1) && (random < 2)) index = 2;
             else if (random>3) index = 3;
             x = temp.i + movement[index][0];
             y = temp.j + movement[index][1];
         }*/
         for(int k = 0; k<4; k++){
             System.out.println("k =" +k);
             int x = temp.i + movement[k][0];
             System.out.println("x =" +x);
             int y = temp.j + movement[k][1];
             System.out.println("y =" +y);
             if(x<0 || x>=M || y<0 || y>=N)continue;
             if(adjacencyMatrix[x][y]==0)continue;
             orderOfVisits.add(new IJ(x,y));             
             stack.push(new IJ(x,y));

             adjacencyMatrix[temp.i][temp.j] = 0;
             System.out.println("visited "+ x + " "+ y);
         }

     }


 }

Полный код:

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package nuevolaberinto;

import java.util.ArrayList;
import java.util.Stack;

/**
 *
 * @author talleres
 */

class IJ {

    int i;
    int j;

    IJ (int i,int j){
        i = this.i;
        j= this.j;
        visited=false;

    }

    boolean visited;

}




class Graph {

    int M;
    int N;

    int adjacencyMatrix[][];

    ArrayList <IJ> orderOfVisits;

    Graph(int M,int N){

        this.M=M;
        this.N=N;
        adjacencyMatrix=new int[M][N];

        for (int i=0; i<M; i++)
            for (int j=0;j<N;j++){
                    adjacencyMatrix[i][j]=-1; //mark all vertices as not visited
            }

        orderOfVisits = new ArrayList<IJ>();

    }




 void DFS_I(int i, int j){ // receives starting position

     IJ aux = new IJ (i,j);

     int [][] movement = {{0,1},{1,0},{0,-1},{-1,0}};

     Stack <IJ> stack = new Stack();

     stack.push(aux);




     double random;
     while(!stack.empty()){

         IJ temp = (IJ)stack.peek();
         stack.pop(); 


         //random=(Math.random()*4);
         //System.out.println("stack size "+ stack.size());

        /* int index = 0;
         if ((random>=0)&&(random<1)) index = 1;
         else if((random >= 1) && (random < 2)) index = 2;
         else if (random>3) index = 3;
         int x = temp.i + movement[index][0];
         int y = temp.j + movement[index][1];
         while(x<0 || x>=M || y<0 || y>=N){
             random=(Math.random()*4);
             index = 0;
             if ((random>=0)&&(random<1)) index = 1;
             else if((random >= 1) && (random < 2)) index = 2;
             else if (random>3) index = 3;
             x = temp.i + movement[index][0];
             y = temp.j + movement[index][1];
         }*/
         for(int k = 0; k<4; k++){
             System.out.println("k =" +k);
             int x = temp.i + movement[k][0];
             System.out.println("x =" +x);
             int y = temp.j + movement[k][1];
             System.out.println("y =" +y);
             if(x<0 || x>=M || y<0 || y>=N)continue;
             if(adjacencyMatrix[x][y]==0)continue;
             orderOfVisits.add(new IJ(x,y));             
             stack.push(new IJ(x,y));

             adjacencyMatrix[temp.i][temp.j] = 0;
             System.out.println("visited "+ x + " "+ y);
         }

     }


 }



 void DFS(int i, int j){ // i,j identifies the vertex

     boolean northValid= false;
     boolean southValid= false;
     boolean eastValid = false;
     boolean westValid = false;


     int iNorth, jNorth;
     int iSouth, jSouth;
     int iEast, jEast;
     int iWest, jWest;

     iNorth=i-1;
     if (!(iNorth<0)) northValid=true;

     iSouth=i+1;
     if(!((iSouth)>=M)) southValid=true;

     jEast=j+1;
     if(!((jEast)>=N)) eastValid=true;

     jWest= j-1;
     if (!(jWest<0)) westValid=true;


    if (adjacencyMatrix[i][j]==-1){ //if the vertex is unvisited

        adjacencyMatrix[i][j]=0; //mark the vertex as visited
        IJ ij = new IJ(i,j);
        orderOfVisits.add(ij); //add the vertex to the visit list
        System.out.println("Visit i,j: " + i +" " +j);



        Double lottery = Math.random();

       for (int rows=i; rows<M; rows++)
           for (int cols=j; cols<N; cols++){


        if (lottery>0.75D){
            if(northValid)
            {
                DFS(iNorth,j);
            }

            if(southValid){
                DFS(iSouth,j);
            }

            if(eastValid){
                DFS(i, jEast);
            }

            if(westValid){
                DFS(i,jWest);
            }


        }

       else if (lottery<0.25D)
       {

            if(westValid){
                DFS(i,jWest);
            }

             if(eastValid){
                DFS(i, jEast);
            }

             if(southValid){
                DFS(iSouth,j);
            }

            if(northValid)
            {
                DFS(iNorth,j);
            }

       }

       else if ((lottery>=0.25D)&&(lottery<0.5D))
       {

             if(southValid){
                DFS(iSouth,j);
            }

             if(eastValid){
                DFS(i, jEast);
            }

            if(westValid){
                DFS(i,jWest);
            }

            if(northValid){
                DFS(iNorth,j);
            }

       }

        else if ((lottery>=0.5D)&&(lottery<=0.75D))
       {

            if(eastValid){
                DFS(i, jEast);
            }

            if(westValid){
                DFS(i,jWest);
            }

            if(southValid){
                DFS(iSouth,j);
            }

            if(northValid){
                DFS(iNorth,j);
            }

       }

    }

 } //end nested for

} //end DFS

//
}


public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here



    Graph theGraph = new Graph(3,3);
    theGraph.DFS_I(0, 0);
   // theGraph.DFS(0,0);



    }

}

Answer 1

Та же проблема, что и у других почта

IJ (int i,int j){
    //i = this.i;
    //j= this.j;
    this.i = i;
    this.j = j;
    visited=false;

}