Question

所以我用Java编写了一个基本的二进制树，并遇到了一个问题。该计划的目标是“学习”新问题，以便猜出类似于20个问题的动物。但是，我不知道如何“保存”节点，以便下次运行时可以通过同一个类调用它。有关如何执行此操作的任何提示或示例？（另外，如果您发现任何其他明显错误，请随时批评/评论）

public class LearningTree {
Node root;

public void addNode(double key, String name){
    Node newNode = new Node(key, name);

    if (root == null){
        root = newNode;
    } else {
        Node focusNode = root;

        Node parent;

        while(true){
            parent = focusNode;`enter code here`

            if(key < focusNode.key){
                focusNode = focusNode.leftChild;

                if(focusNode == null){
                    parent.leftChild = newNode;
                    return;
                }
            } else {
                focusNode = focusNode.rightChild;

                if(focusNode == null){
                    parent.rightChild = newNode;
                    return;
                }
            }

        }
    }
}
 public void traverse(Node focusNode){
 if(focusNode != null){

     traverse(focusNode.leftChild);

     traverse(focusNode.rightChild);
 }
 }


 class Node{

 double key;
 String name;

 Node leftChild;
 Node rightChild;

 Node(double key, String name){
     this.key = key;
     this.name = name;
 }

}

public void keyChange(Node focusNode, double newkey){
focusNode.key = newkey;
 }

public Node findNode(double key) {



 Node focusNode = root;

    while (focusNode.key != key) {


      if (key < focusNode.key) {

          focusNode = focusNode.leftChild;

          } else {

              focusNode = focusNode.rightChild;
          }

          if (focusNode == null)
                return null;

}

   return focusNode;

}


 public static void main(String[] args){
 LearningTree Tree = new LearningTree();
 Scanner sc = new Scanner(System.in);

 //Nodes
 Tree.addNode(1500, "Does it have wings?");
 Tree.addNode(750, "Is it a dog?");



 System.out.println("Is it an animal?");

 double n = 1000;

 while(true){
 String Answer = sc.nextLine();
 String answer = Answer.toLowerCase();

 double k = n;


 if(answer.equals("y")){
     n = 1.5* n;
 }
 if(answer.equals("n")){
     n = .5*n;
 }
 if(Tree.findNode(n) != null){

 System.out.println(Tree.findNode(n).name + " (y/n)");
 }

 if(Tree.findNode(n) == null){
     System.out.println("What is it?");
     String answer1 = sc.nextLine();
     System.out.println("What would distinguish a " + answer1 + "from the     previous guess?");
     String answer2 = sc.nextLine();
     System.out.println("What would the answer be to " + answer2 + "? (y/n)");
     String answer3 = sc.nextLine();
     double s;

     if(Tree.findNode(k/1.5) == null){
         Tree.findNode(k/.5);
     } else {
         Tree.findNode(k/1.5);
     }

     if(answer3.equals("y")){
         Tree.keyChange(Tree.findNode(k), n );
         s = 1.5;
         Tree.addNode(n, Tree.findNode(n).name);
     }

     if(answer3.equals("n")){
             Tree.keyChange(Tree.findNode(k), n);
             s = .5;
             Tree.addNode(n, Tree.findNode(n).name );
     }
     Tree.addNode(k, answer2);






            }


     }





 }



 }

Answer 1

您可能希望将此对象序列化为文件，以便下次通过反序列化运行时可以将数据恢复。检查ObjectOutputstream类的文档。说过你需要有一些逻辑，

Answer 2

也许您可以使用本地文件并序列化数据。 Java处理得非常好。

注意：我没有测试过这段代码，但它是一个起点。

private void saveNode(Node n){
    FileOutputStream fout = new FileOutputStream("file.txt");
    ObjectOutputStream oos = new ObjectOutputStream(fout);
    oos.writeObject(n);
    oos.close();
}

private Node readNode(){
   FileInputStream fin = new FileInputStream("file.txt");
   ObjectInputStream ois = new ObjectInputStream(fin);
   Node n = (Node)ois.readObject();
   ois.close();
   return n;
}

如何保存节点

2 个答案: