Question

在开始之前，我只想先写一下这是我在stackoverflow上的第一篇文章。

我正在为类的二叉搜索树工作。我有一个插入函数完成，以及打印节点的遍历。但是，我收到一个错误，阻止我编译测试我的树。这是我的.h文件，它是一个模板，所以一切都包含在这里。

我收到LNK错误，而且从我所读过的内容来看，我仍然无法理解为什么会这样。

错误3错误LNK2019：未解析的外部符号＆＃34; private：void __thiscall main_dc :: BST :: helperInOrder（struct main_dc :: Node *＆amp;）＆＃34;函数＆＃34; public：void __thiscall main_dc :: BST :: traversalInOrder（void）＆＃34;（？helperInOrder @？$ BST @H @ main_dc @@ AAEXAAPAU？$ Node @ H @ 2 @@ Z）（？traversalInOrder @？$ BST @H @ main_dc @@ QAEXXZ）\ codingpc \ Users \ Devyn \ Documents \ Visual Studio 2013 \ Projects \ 2420_Data_And_Algorithm \ BinarySearchTree_Project_07 \ BinarySearchTree_Project_07 \ Driver.obj BinarySearchTree_Project_07

template <class T>
class BST
{
public:
    BST();
    ~BST(); // delete root that deletes left and right child

    int getSize();
    void print();
    void erase(T item); // item is an integer number
    void insert(T item);

    // Traversal functions (pre-order, in-order, post-order)
    // void traverselPreOrder();
    void traversalInOrder();
    void traversalPostOrder();

private:
    // Helper function for insert
    void insertHelper(Node<T>*& n, T item);

    //Traversal helper functions
    void helperPostOrder(Node<T>*& n);
    void helperInOrder(Node<T>*& n);

    // member data
    Node<T>* root;
    int size;
};

    template <class T>
BST<T>::BST()
{
    root = nullptr;
    size = 0;
}

template <class T>
BST<T>::~BST()
{
    // delete root;
}

template <class T>
int BST<T>::getSize()
{
    // return size;
    // return number of elements in the tree
}

template <class T>
void BST<T>::print()
{
    // pre order traversal
    // print one element per line
    // indent according to the depth (see page 505)
}

template <class T>
void BST<T>::traversalInOrder()
{
    helperInOrder(root);
}

template <class T>
void helperInOrder(Node<T>*& nPtr)
{
    // something in tree - if root != null
    if (root != nullptr)
    {
        // if root != null... if left child pointer != null, recursively call helper, passing ptrs left
        if (nPtr->lchild != nullptr)
        {
            helperInOrder(nPtr->lchild);
        }
        // print out current node
        cout << nPtr->data;
        if (nPtr->rchild != nullptr)// if right child pointer != null, recursively call helper, passing ptrs right
        {
            helperInOrder(nPtr->rchild)
        }           
    }
    else // else tree is empty print out tree is empty
    {
        cout << "The tree is empty" << endl;
    }   
}

template <class T>
void BST<T>::erase(T item)
{
    // erase the occurrence of the item in the tree (there should only be 1 
    // or 0 because there are no dupes)
    // resulting tree should still be a binary search tree (balanced AND full?)
}

template <class T>
void BST<T>::insert(T item)
{
    insertHelper(root, item);
}

template <class T>
void BST<T>::insertHelper(Node<T>*& nPtr, T item) // insert an item into BTS, do not allow duplicate numbers
{
    if (root == nullptr) // if nothing in tree - insert node
    {
        root = new Node<T>(item);
    }
    // if something in tree - check to see if less or greater than node you are on
    else if (item < nPtr->data) // if item is less than data in node and nothing is in lchild, create a node
    {
        if (nPtr->lchild != nullptr) // if left child has a value, traverse left once
        {
            insertHelper(nPtr->lchild, item);
        }
        else
        {
            nPtr->lchild = new Node<T>(item);
        }
    }
    else if (item > nPtr->data) // if item is greater than data node and nothing is in rchild, create a node
    {
        if (nPtr->rchild != nullptr) // if right child already exsists, traverse right once
        {
            insertHelper(nPtr->rchild, item);
        }
        else
        {
            nPtr->rchild = new Node<T>(item);
        }
    }
    else // parent has no place for item to go
    {
        cout << "The input " << item << " has already been added to the tree." << endl;
    }
}

}

Answer 1

缺少类范围 void helperInOrder（Node *＆amp; nPtr）

错误LNK2019未解析外部符号

1 个答案: