@SuppressWarnings("unused")
	private void setPositions() {
		
		int numOfWalls 	= ((rows*columns))*3/4;
		walls 			= new int[numOfWalls][2];		
		boolean go = true; 
		Random rand = new Random();
		ArrayList<int[]> usedWalls = new ArrayList<int[]>();
		
		//int start[] = new int[2];
/*		start_s[0] = rand.nextInt(rows-2)+1;
		start_s[1] = rand.nextInt(columns-2)+1;
		
		//int goal[] = new int[2];
		goal_s[0] = rand.nextInt(rows-2)+1;
		goal_s[1] = rand.nextInt(columns-2)+1;
*/		
		for(int i=0;i<numOfWalls;i++){			
			go = true;
			while(go){
				int w[] = new int[2];
				w[0] = rand.nextInt(rows-2)+1;
				w[1] = rand.nextInt(columns-2)+1;

				if(!(usedWalls.contains(w))){
					go = false;
					usedWalls.add(w);
					walls[i][0] = w[0];
					walls[i][1] = w[1];
				}
			}
		}
	}