Question

我在二叉搜索树上做作业。我们获得了一个头文件，我们不允许改变它。

我有一个创建BST的功能，其中包含要存储的初始值，一个通过复制现有树来创建BST的函数以及一个插入BST的函数。

我正在努力找出什么是错的，我在网上寻求帮助的地方总是有不同的头文件我不能做。任何帮助将不胜感激。

#include "stdafx.h"
#include "bst.h"

// Creating nodes  
Node* tree;
Node* treeNew;


// Creates an empty binary tree - 1
BinarySearchTree::BinarySearchTree()
{
    treeNew = nullptr;
}

// Creates a binary tree with an initial value to store - 2
BinarySearchTree::BinarySearchTree(std::string word)
{
    Node *tree = new Node;
    tree->left = nullptr;
    tree->right = nullptr;
    tree->data = word;
}

// Creates a binary tree by copying an existing tree - 3
BinarySearchTree::BinarySearchTree(const BinarySearchTree &rhs)
{
    if (tree != NULL) {

        Node *treeNew = new Node;
        treeNew->data = tree->data;

        Node *leftTreeNew = new Node;
        leftTreeNew = tree->left;

        Node *rightTreeNew = new Node;
        rightTreeNew = tree->right;
    }
    else {
        treeNew = NULL;
    }
}

// Adds a word to the tree
void BinarySearchTree::insert(std::string word)
{
    Node *nextNode = tree;
    Node *currentNode;


    while (nextNode != NULL) {
        currentNode = nextNode;

        if (word < currentNode->data) {
            nextNode = currentNode->left;
        } else {
            nextNode = currentNode->right;
        }
    } 
}

这是我的头文件

#pragma once

#include <iostream>
#include <string>

// Node of the tree
struct Node
{
    // Data stored in this node of the tree
    std::string data;
    // The left branch of the tree
    Node *left = nullptr;
    // The right branch of the tree
    Node *right = nullptr;
};

class BinarySearchTree
{
private:
    // Pointer to root of the tree
    Node *root = nullptr;
public:
    // Creates an empty binary tree
    BinarySearchTree();
    // Creates a binary tree with an inital word to store
    BinarySearchTree(std::string word);
    // Creates a binary tree by copying an existing tree
    BinarySearchTree(const BinarySearchTree &rhs);
    // Destroys (cleans up) the tree
    ~BinarySearchTree();
    // Adds a word to the tree
    void insert(std::string word);
    // Removes a word from the tree
    void remove(std::string word);
    // Checks if a word is in the tree
    bool exists(std::string word) const;
    // Creates a string representing the tree in alphabetical order
    std::string inorder() const;
    // Creates a string representing the tree in pre-order
    std::string preorder() const;
    // Creates a string representing the tree in post-order
    std::string postorder() const;
    // Checks if two trees are equal
    bool operator==(const BinarySearchTree &other) const;
    // Checks if two trees are not equal
    bool operator!=(const BinarySearchTree &other) const;
    // Reads in words from an input stream into the tree
    friend std::istream& operator>>(std::istream &in, BinarySearchTree &tree);
    // Writes the words, in-order, to an output stream
    friend std::ostream& operator<<(std::ostream &out, const BinarySearchTree &tree);
};

Answer 1

您的代码存在许多错误，您需要更正它们。

例如，

在函数insert（std :: string word）中，如果树为null，则无需执行任何操作，但实际上您应该创建一个节点（值为＆＃34; word＆＃ 34;）并插入它。同样，根可能会有时改变，你必须考虑它。
在函数BinarySearchTree（const BinarySearchTree＆amp; rhs）中，你永远不会使用rhs。此外，我猜你的意思是深层次的，所以你的代码根本无法工作。

我的建议是你应该重写你的功能（在充分了解BST之后）。同时，您可以尽快清楚地描述您的问题。

二进制搜索树不可更改的头文件

1 个答案: