为什么使用此二叉树的概率如此之高？ - java

它基本上只是霍夫曼编码算法的一种实现，但是当我检查BinaryTree结束(队列中剩下的唯一项目)的概率很高时。

// Make a BinaryTree for each item in CharOccurrences and add as an entry in initialQueue
for (int i = 0; i < charOccurrences.size(); i++) {
  BinaryTree<CharProfile> bTree = new BinaryTree<CharProfile>();
  bTree.makeRoot(charOccurrences.get(i));
  initialQueue.add(bTree);
}

// Create the BinaryTree that we're adding to the resultQueue
BinaryTree<CharProfile> treeMerge = new BinaryTree<CharProfile>();

// Create the CharProfile that will hold the probability of the two merged trees
CharProfile data;

while (!initialQueue.isEmpty()) {
  // Check if the resultQueue is empty, in which case we only need to look at initialQueue
  if (resultQueue.isEmpty()) {
    treeMerge.setLeft(initialQueue.remove());
    treeMerge.setRight(initialQueue.remove());

    // Set treeMerge's data to be the sum of its two child trees' probabilities with a null char value
    data = new CharProfile('\0');
    data.setProbability(treeMerge.getLeft().getData().getProbability() + treeMerge.getRight().getData().getProbability());
    treeMerge.setData(data);
  }
  else {
    // Set the left part of treeMerge to the lowest of the front of the two queues
    if (initialQueue.peek().getData().getProbability() <= resultQueue.peek().getData().getProbability()) {
      treeMerge.setLeft(initialQueue.remove());
    }
    else {
      treeMerge.setLeft(resultQueue.remove());
    }

    if (!initialQueue.isEmpty()) {
      // Set the right part of treeMerge to the lowest of the front of the two queues
      if (initialQueue.peek().getData().getProbability() <= resultQueue.peek().getData().getProbability()) {
        treeMerge.setRight(initialQueue.remove());
      }
      else {
        treeMerge.setRight(resultQueue.remove());
      }
    }
    // In the case that initialQueue is now empty (as a result of just dequeuing the last element), simply make the right tree resultQueue's head
    else {
      treeMerge.setRight(resultQueue.remove());
    }

    // Set treeMerge's data to be the sum of its two child trees' probabilities with a null char value
    data = new CharProfile('\0');
    data.setProbability(treeMerge.getLeft().getData().getProbability() + treeMerge.getRight().getData().getProbability());
    treeMerge.setData(data);
  }

  // Add the new tree we create to the resultQueue
  resultQueue.add(treeMerge);
}

if (resultQueue.size() > 1) {
  while (resultQueue.size() != 1) {
    treeMerge.setLeft(resultQueue.remove());
    treeMerge.setRight(resultQueue.remove());

    data = new CharProfile('\0');
    data.setProbability(treeMerge.getLeft().getData().getProbability() + treeMerge.getRight().getData().getProbability());
    treeMerge.setData(data);

    resultQueue.add(treeMerge); 
  }
}

然后，我在结尾处有这个:

System.out.println("\nProbability of end tree: " 
    + resultQueue.peek().getData().getProbability());

这给了我:

结束树的概率:42728.31718061674

参考方案

在while循环内移动以下行:

// Create the BinaryTree that we're adding to the resultQueue
BinaryTree<CharProfile> treeMerge = new BinaryTree<CharProfile>();

否则，一个迭代将treeMerge添加到resultQueue，而下一个迭代可能执行treeMerge.setLeft(resultQueue.remove());，这使得treeMerge成为其自身的子代...

Java-向Servlet动态添加URL模式 - java

是否可以在运行时动态地将URL模式添加到Servlet？例如，当Servlet启动时，扫描文件夹中的注释，然后将这些URL模式注入到Servlet中？提供更多清晰度-在Servlet的init文件中，我要执行此操作（伪代码）// scan all the files in the package my.project.services // find all…

Java:正则表达式模式匹配器是否有大小限制？ - java

我的模式类似于OR:“word1 | word2 | word3”我大约有800个字。可能有问题吗？ 参考方案 您仅受记忆和理智的限制。 :)

Java:线程池如何将线程映射到可运行对象 - java

试图绕过Java并发问题，并且很难理解线程池，线程以及它们正在执行的可运行“任务”之间的关系。如果我创建一个有10个线程的线程池，那么我是否必须将相同的任务传递给池中的每个线程，或者池化的线程实际上只是与任务无关的“工人无人机”可用于执行任何任务？无论哪种方式，Executor / ExecutorService如何将正确的任务分配给正确的线程？ 参考方案 …

Java:我可以在Hashmaps中使用数组吗？ - java

我可以在Hashmaps中使用数组吗？如果是这样，则声明这种哈希图的确切语法是什么？谢谢 参考方案 数组也是对象。甚至像int[]这样的原始数组。Map<String,String[]> map = new HashMap<String,String[]>();

JAVA:字节码和二进制有什么区别？ - java

java字节代码（已编译的语言，也称为目标代码）与机器代码（当前计算机的本机代码）之间有什么区别？我读过一些书，他们将字节码称为二进制指令，但我不知道为什么。 参考方案 字节码是独立于平台的，在Windows中运行的编译器编译的字节码仍将在linux / unix / mac中运行。机器代码是特定于平台的，如果在Windows x86中编译，则它将仅在Win…