Question

我们有一项创建二进制搜索树的任务，其中包含一些基本功能。如果对于我们需要遵守的作业中包含的文件，我觉得我能够抓住，以便评分者用他们的评分程序实现我们的代码。学生将获得一个名为＆＃34; Factory.cpp＆＃34;它有一个函数，试图返回＆＃34; BinarySearchTree＆＃34; （return new BinarySearchTree();）。但是，VS 2013给了我标题中看到的错误。经过一些研究，我无法找到任何可以在我自己的问题中实现的信息来摆脱错误。模板类显然更抽象，我无法找出要包含/遗漏的内容等，以使事情有效。

以下是我目前在BinarySearchTree.h中的不完整代码：

#pragma once
#include "BSTInterface.h"
#include "NodeInterface.h"

#ifndef BINARY_SEARCH_TREE_H
#define BINARY_SEARCH_TREE_H

    struct BTNode :public NodeInterface{
        // Data Fields
        int data;
        BTNode* left;
        BTNode* right;

        // Constructor
        BTNode(const int& the_data,
            BTNode* left_val = NULL,
            BTNode* right_val = NULL) :
            data(the_data), left(left_val), right(right_val) {}

        // Destructor (to avoid warning message)
        virtual ~BTNode() {}

        // Interface Functions
        int getData(){
            return data;
        }

        NodeInterface* getLeftChild(){
            return left;
        }

        NodeInterface* getRightChild(){
            return right;
        }

    }; // End BTNode



#include <sstream>

template<class T>
class BinarySearchTree:public BSTInterface
{

public:
    BTNode* root;
    // BST Constructor / Deconstructor
    BinarySearchTree() : root(NULL){}

    //BinarySearchTree(const int& the_data,
    //  const BinarySearchTree& left_child = BinarySearchTree(),
    //  const BinarySearchTree& right_child = BinarySearchTree()) :
    //  root(new BTNode(the_data, left_child.root, right_child.root)){}

    virtual ~BinarySearchTree(){}

    // Interface Functions ----------------------

    NodeInterface* getRootNode(){
        return root;
    }


    bool add(int data){
        return addRec(root, data);
    }


    bool addRec(BTNode* &x, int data){
        if (x == NULL){
            if (Search(root, data) == true){
                return false;
            }
            else{
                root = GetNewNode(data);
                return true;
            }
        }
        if (data == x->data){
            return false;
        }
        if (x != NULL){
            if (data < x->data){
                return addRec(x->left, data);
            }
            if (data > x->data){
                return addRec(x->right, data);
            }
        }
    }


    bool remove(int data){
        return false;
    }


    bool removeRec(BTNode* &x, int data){
        return false;
    }


    void clear(){

    }
    // ------------------------------------------


    // My Functions -----------------------------

    BTNode* GetNewNode(int data){
        BTNode* newNode = new BTNode();
        newNode->data = data;
        newNode->left = newNode->right = NULL;
        return newNode;
    }

    bool Search(BTNode* root, int data) {
        if (root == NULL) {
            return false;
        }
        else if (root->data == data) {
            return true;
        }
        else if (data < root->data) { // had <= instead
            return Search(root->left, data);
        }
        else if (data > root->data) { // had no "if"
            return Search(root->right, data);
        }
    }
    // ------------------------------------------
};
#endif

这是从以下2＆＃34;接口＆＃34;文件：

NodeInterface.h：

//YOU MAY NOT MODIFY THIS DOCUMENT    
#pragma once    
#include <iostream>    
class NodeInterface {
public:
    NodeInterface() {}
    virtual ~NodeInterface() {}

    /*Returns the data that is stored in this node*/
    virtual int getData() = 0;

    /*Returns the left child of this node or null if it doesn't have one.*/
    virtual NodeInterface * getLeftChild() = 0;

    /*Returns the right child of this node or null if it doesn't have one.*/
    virtual NodeInterface * getRightChild() = 0;

};

BSTInterface.h

//YOU MAY NOT MODIFY THIS DOCUMENT    
#pragma once    
#include "NodeInterface.h"  
using namespace std;    
class BSTInterface {
public:
    BSTInterface() {}
    virtual ~BSTInterface() {}

    //Please note that the class that implements this interface must be made
    //of objects which implement the NodeInterface

    /*Returns the root node for this tree*/
    virtual NodeInterface * getRootNode() = 0;

    /*Attempts to add the given int to the BST tree*/
    virtual bool add(int data) = 0;

    /*Attempts to remove the given int from the BST tree*/
    virtual bool remove(int data) = 0;

    /*Removes all nodes from the tree, resulting in an empty tree.*/
    virtual void clear() = 0;
};

然后他们给我们＆＃34; Factory.h＆＃34;和＆＃34; Factory.cpp，＆＃34;我认为他们使用它来获取我们的BinarySearchTree，以便使用他们的评分程序进行评分：

Factory.h：

    #include "BSTInterface.h"
    using namespace std;
    /*
    WARNING: It is expressly forbidden to modify any part of this document, including its name
    */

    class Factory
    {
    public:
        static BSTInterface * getBST();
    };

Factory.cpp：

#include "Factory.h"
#include "BinarySearchTree.h"
//You may add #include statements here

/*
    You will MODIFY THIS DOCUMENT.

    getBST()
    Creates and returns an object whose class extends BSTInterface.
    This should be an object of a class you have created.
    Example: If you made a class called "BinarySearchTree", you might say, "return new BinarySearchTree();".
*/
BSTInterface * Factory::getBST()
{
    return new BinarySearchTree();//Modify this line
}

在＆＃34; Factory.cpp＆＃34;中，BinarySearchTree在VS中被标记为错误，并且消息＆＃34;缺少类模板的参数列表。＆＃34;我该如何解决？连同您看到的任何其他错误。

另外，我如何在main()中声明一个新的BinarySearchTree对象并调用它的函数来测试它？

Answer 1

对于该错误，请参阅以下行：

template<class T>
class BinarySearchTree:public BSTInterface
{

刚刚摆脱第一线。该行告诉编译器您BinarySearchTree类是模板类。但由于您的班级使用int数据，因此似乎不需要。

我没有看过你的其他代码所以我不会评论任何其他代码。

返回新的BinarySearchTree - 缺少类模板的参数列表

1 个答案: