从文件读入二进制树并写入文件

Question

我正在读入一个名为“Lincoln.txt”的二进制树，并将它们按照字母顺序放入我的树中，我应该写这个词和将该单词计数到名为“index.txt”的文件。现在，我可以将它们读入我的二叉树中没有问题，但我不太清楚如何将它们写入“index.txt”。完成后我检查我的文件，我得到的都是地址。你能帮我吗？

这里是我的编码：

的main.cpp

#include <iostream> 
#include "NodeClass.h" 
#include <fstream> 

using namespace std; 

int main() 
{ 
    string myString; 
    BinaryTree myTree(""); 
    ifstream infile; 

    infile.open("Lincoln.txt"); 

    while(infile) 
    { 
     infile >> myString; 
     myTree.insert(myString, myTree.root); 
    } 

    ofstream outFile; 

    outFile.open("index.txt"); 

    myTree.print(myTree.root, outFile); 

    outFile.close(); 
} 

NodeClass.cpp

#include <iostream> 
#include "NodeClass.h" 

using namespace std; 

void BinaryTree::insert(ElementType data, TreeNode *&tree) 
{ 
    if (tree == NULL) 
    { 
     tree = new TreeNode(data); 
    } 
    else if(data < tree->data) 
     insert(data, tree->left); 
    else if(data > tree->data) 
     insert(data, tree->right); 
    else if(data == tree->data) 
     tree->count++; 

} 

void BinaryTree::display(TreeNode *tree, ostream& out) 
{ 
    if (tree != NULL) 
    { 
     display(tree->left, out); 
     out << tree->data<<" "; 
     display(tree->right, out); 
    } 
} 

void BinaryTree::print(TreeNode *tree, ofstream& outFile) 
{ 

    if (tree != NULL) 
    { 
     outFile << tree->left; 
     outFile << tree->data << " " << tree->count; 
     outFile << tree->right; 
    } 

} 

NodeClass.h

#include <iostream> 
#include <string> 
#include <fstream> 
#include <fstream> 

using namespace std; 

#ifndef TREENODE_H 
#define TREENODE_H 

typedef std::string ElementType; 

class BinaryTree 
{ 
public: 
    class TreeNode 
    { 
    public: 
     ElementType data; 
     int count; 
     TreeNode *left; 
     TreeNode *right; 
     TreeNode(ElementType new_data) 
      { data = new_data; left = NULL; right = NULL;};  
    }; 
TreeNode *root; 
BinaryTree(ElementType root_data) 
    { root = new TreeNode(root_data); }; 
~BinaryTree() { delete root;}; 
void insert(ElementType data, TreeNode *&tree); 
void display(TreeNode *tree, ostream& out); 
void print(TreeNode *tree, ofstream& outFile); 
}; 

#endif TREENODE_H 

Lincoln.txt

The Gettysburg Address 



       Gettysburg, Pennsylvania 

       November 19, 1863 





Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in 

Liberty, and dedicated to the proposition that all men are created equal. 



Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and 

so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate 

a portion of that field, as a final resting place for those who here gave their lives that that nation 

might live. It is altogether fitting and proper that we should do this. 



But, in a larger sense, we can not dedicate -- we can not consecrate -- we can not hallow -- this ground. 

The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add 

or detract. The world will little note, nor long remember what we say here, but it can never forget what 

they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they 

who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great 

task remaining before us -- that from these honored dead we take increased devotion to that cause for 

which they gave the last full measure of devotion -- that we here highly resolve that these dead shall not 

have died in vain -- that this nation, under God, shall have a new birth of freedom -- and that government 

of the people, by the people, for the people, shall not perish from the earth. 

写index.txt之后，这是我得到：

00000000 -8421504510035D230 

编辑：我的教授说我的打印功能应该是一个递归函数，但我不知道该怎么做。

Answer 1

您需要递归遍历所有节点并打印它们。尝试这个。

void BinaryTree::print(TreeNode *tree, ofstream& outFile) 
{ 
    if (tree != NULL) 
    { 
     print(tree->left, outfile); 
     outFile << tree->data << " " << tree->count << "."; 
     print(tree->right, outfile); 
    } 
} 

参考wiki了解究竟如何穿越工程。上面给出的称为Inorder traversal。

1. 遍历左子树第一
2. 遍历根
3. 遍历右子树第一