Question

我正在制作这个Android应用程序，需要使用A star算法解决puzzle8。为了实现这一点，我使用了一个比较器，如下所示：

public class PuzzleBoardComparator implements Comparator<PuzzleBoard> {
@Override
public int compare(PuzzleBoard A, PuzzleBoard B) {
    Integer priorityA=A.priority();
    Integer priorityB=B.priority();
    if(priorityA.compareTo(priorityB)<0)
        return -1;
    if(priorityA.compareTo(priorityB)>0)
        return 1;
    else
        return 0;
    }
}

此comaparator使用基于计算曼哈顿距离的优先级（），如下所示：

public int priority() {
    int manhattanDistance=0;
    for(int x=0;x<NUM_TILES;x++){
        for(int y=0;y<NUM_TILES;y++){
              if(tiles.get(XYtoIndex(x,y))!=null){
                    int numTile=tiles.get(XYtoIndex(x,y)).getNumber();
                    numTile-=1;
                    int xNumTile=numTile/NUM_TILES;
                    int yNumTile=numTile%NUM_TILES;
                    manhattanDistance+=Math.abs(x-xNumTile)+Math.abs(y-yNumTile);
              }
        }
    }
    return manhattanDistance+steps;
}

现在，这是解决这个难题的A-star算法的实现：

public void solve() {
    //Log.d("DEMO1","LOOP");
    PuzzleBoardComparator comparator=new PuzzleBoardComparator();
    //Log.d("DEMO2","LOOP");
    PriorityQueue<PuzzleBoard> queue=new PriorityQueue<>(10,comparator);
    //Log.d("DEMO3","LOOP");
    puzzleBoard.steps=0;
    puzzleBoard.previousBoard=null;
    queue.add(puzzleBoard);
    while(!queue.isEmpty()){
          //Log.d("DEMO4","LOOP");
          PuzzleBoard cBoard=queue.remove();
          if(cBoard.resolved()){
               ArrayList<PuzzleBoard> solution=new ArrayList<>();
               //solution.add(cBoard);
               while(cBoard.getParent()!=null){
                     solution.add(cBoard);
                     cBoard=cBoard.getParent();
               }
               solution.add(cBoard);
               Collections.reverse(solution);
               animation=solution;
               break;
          }
          ArrayList<PuzzleBoard> neigh;
          neigh=cBoard.neighbours();
          Iterator<PuzzleBoard> it=neigh.iterator();
          while(it.hasNext()){
               queue.add(it.next());
          }
    }
}

但是，我的申请根本不起作用。每当我按下按钮来解决难题时，什么都不会发生。经过一段时间后，我在logcat上收到此错误消息：

07-14 15:14:08.491 6172-6172/com.google.engedu.puzzle8 E/dalvikvm-heap: Out of memory on a 64-byte allocation.
    07-14 15:14:09.482 6172-6172/com.google.engedu.puzzle8 E/dalvikvm-heap: Out of memory on a 184-byte allocation.
    07-14 15:14:09.662 6172-6172/com.google.engedu.puzzle8 E/AndroidRuntime: FATAL EXCEPTION: mainProcess: com.google.engedu.puzzle8, PID: 6172
    java.lang.IllegalStateException: Could not execute method of the activity
    at android.view.View$1.onClick(View.java:3823)
    at android.view.View.performClick(View.java:4438)
    at android.view.View$PerformClick.run(View.java:18422)
    at android.os.Handler.handleCallback(Handler.java:733)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:136)
    at android.app.ActivityThread.main(ActivityThread.java:5017)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
    at dalvik.system.NativeStart.main(Native Method)
    Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at android.view.View$1.onClick(View.java:3818)
    at android.view.View.performClick(View.java:4438) 
    at android.view.View$PerformClick.run(View.java:18422) 
    at android.os.Handler.handleCallback(Handler.java:733) 
    at android.os.Handler.dispatchMessage(Handler.java:95) 
    at android.os.Looper.loop(Looper.java:136) 
    at android.app.ActivityThread.main(ActivityThread.java:5017) 
    at java.lang.reflect.Method.invokeNative(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:515) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) 
    at dalvik.system.NativeStart.main(Native Method) 
    Caused by: java.lang.OutOfMemoryError: [memory exhausted]
    at dalvik.system.NativeStart.main(Native Method)

请帮我解决问题

编辑1：这是存在onclick属性的xml文件的元素。

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/solve_button_label"
    android:id="@+id/solve_button"
    android:onClick="solve"
    android:layout_alignParentBottom="true"
    android:layout_toRightOf="@+id/shuffle_button"
    android:layout_toEndOf="@+id/shuffle_button" />

编辑2：这是项目https://github.com/akhileshydv/Puzzle8.git

的github链接

Answer 1

您需要在manifest.xml中添加此行

<application
      android:largeHeap="true">

java.lang.OutOfMemoryError：android中的[内存耗尽]

1 个答案: