河内塔，停止滑动 [英] Tower of Hanoi, stop sliding

问题描述

我为河内塔问题开发了解决方案:

I developed a solution for the Tower of Hanoi problem:

public static void bewege(int h, char quelle, char ablage, char ziel) {  
  if(h > 0){
     bewege(h - 1, quelle, ziel, ablage);
     System.out.println("Move "+ h +" from " + quelle + " to " + ziel);
     bewege(h - 1, ablage, quelle, ziel);
 }
}

工作正常.现在，我想限制幻灯片的数量，如果达到一定的限制，则引发异常.我用一个计数器尝试了它，但是它不起作用:

It works fine. Now i want to limit the number of slides and throw an exception if a certain limit is reached. I tried it with a counter but it does not work:

class HanoiNK{

 public static void main(String args[]){
   Integer n = Integer.parseInt(args[0]);
   Integer k = Integer.parseInt(args[1]);

   try{
    bewege(k, n, 'A', 'B', 'C');
   }catch(Exception e){
    System.out.println(e);
   }
 }

 public static void bewege(int c, int h, char quelle, char ablage, char ziel) 
    throws Exception{  
  if(h > 0){
   if(c != 0){
   bewege(c, h - 1, quelle, ziel, ablage);
   c--;
   System.out.println("Move "+ h +" from " + quelle + " to " + ziel);
   bewege(c, h - 1, ablage, quelle, ziel);
   c--;
   }else{ 
    throw new Exception("stop sliding");
   }
  }
 }
}

永远不会引发异常.有什么想法吗?

The exception is never thrown. Any ideas?

更新:结果为6张幻灯片，但应为5张 http://ideone.com/lm084

推荐答案

正题:

在我看来，好像counter没有在任何地方定义，因此不应编译.

It looks to me as though counter is not defined anywhere, and so that shouldn't compile.

现在您已经编辑了问题以解决上述问题，如果您的第一个参数大于第二个参数，则会抛出异常，例如:

Now that you've edited your question to fix the above, the exception will be thrown if your first argument is greater than your second argument, e.g.:

java HanoiNK 5 3

在这种情况下，当c == 0和h == 1发生异常.

The exception will occur when c == 0 and h == 1, in that case.

离题:这些行:

Integer n = Integer.parseInt(args[0]);
Integer k = Integer.parseInt(args[1]);

应该是

int n = Integer.parseInt(args[0]);
int k = Integer.parseInt(args[1]);

...因为parseInt返回int(不是Integer)，并且您要传递给它们的函数接受int(不是Integer).自动装箱可能会让您摆脱困境，但这是不必要的.

...since parseInt returns int (not Integer) and the function you're passing them into accepts int (not Integer). Auto-boxing probably lets you get away with it, but it's unnecessary.

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