如何使用重载的 + 运算符组合两个链表？

Question

我试图在不链接的情况下重载 + 运算符，这样我就可以组合两个链表。使用我当前的代码，它似乎根本没有将它们结合起来。

这是我目前重载运算符以组合列表的尝试。

void WORD::operator+ (const WORD & B)
{

    character *p = new character;

    while (p == 0)
    {
        Insert(p->symbol);
    }

}

这是我得到的帮助编写代码的程序头。

#include <iostream>
#include <string>

using namespace std;

#ifndef WORD_H
#define WORD_H

class character
{
public:
    char symbol;
    character *next;
};

class WORD
{
public:
    bool IsEmpty() { return front == 0; };
    int Length(); //Length: Determines the length of the word A; remember A is the current object;
    friend ostream & operator<<(ostream & out, const WORD & org); //Overload the insertion operator as a friend function with chaining to print a word A;
    void operator=(const string & s);// Overload the assignment operator as a member function to take a 
                                       //string (C-style or C++ string, just be consistent in your implementation) as an argument and 
                                       //assigns its value to A, the current object;
    WORD & operator=(const WORD & w); // Overload the assignment operator as a member function with chaining to take a word
                                    //object as an argument and assigns its value to A, the current object;
    void operator+(const WORD & B); //Overload the ‘+” operator as a member function without chaining to add word B 
                                      //(adds the set of symbols that makep B's linked list to the back of A's linked list) to the back of word A; 
                                      //remember A is the current object;
    void WORD::Insert(char key);
    WORD();//The default constructor will initialize your state variables. 
                                     //The front of the linked list is initially set to NULL or 0; this implies a non-header node 
                                     //implementation of the link list.
    WORD(const string & s); //Explicit-value constructor: This constructor will have one argument; 
                               //a C-style string or a C++ string representing the word to be created;
    WORD(const WORD & org);   // Copy Constructor: Used during a call by value, return, or initialization/declaration of a word object;
    ~WORD();                   //Destructor: The destructor will de-allocate all memory allocated for the word. Put the message 
                                 //"destructor called\n" inside the body of the destructor.
    bool IsEqual(const WORD & B);// Returns true if two word objects are equal; otherwise false; remember A is the current

private:
    character *front, *back;
};

#endif

这也是在重载运算符中使用的“插入”函数。

void WORD::Insert(char key) 
{   

    character *p = new character;
    p->next = 0;
    p->symbol = key;

    if (front == 0)
    {
        front = back = p;
    }
    else
    {
        back->next = p;
        back = p;
    }

}

用于测试重载运算符功能的驱动程序。

cout << "************TEST#8*******************************" << endl;
cout << "Adding 2 words by adding us to the back of their.  Their is the current object" << endl;
WORD their("AAAA0000AAA0000AAA");
WORD us("XXXX");
their + us; 
cout<<"their followed by us is \n" <<their<< " = AAAA0000AAA0000AAAXXXX"<<endl;
cout << "*************************************************" << endl;
cout<<endl<<endl;

cout << "************TEST#9*******************************" << endl;;
cout << "Adding 2 words, their2 is empty, by adding us to the back of their.Their is the current object" << endl;;
WORD their2(""); 
their2 + us; 
cout<<"their followed by us is \n" <<their<< " = XXXX"<<endl; 
cout << "*************************************************" << endl;
cout << endl << endl;


cout << "************TEST#10*******************************" << endl;;
cout << "Adding 2 words, their3 is empty, by adding us to the back of their.Their is the current object" << endl;
WORD their3(""); 
us + their3; 
cout << "us followed by empty their3 is \n" << us << " = XXXX" << endl;
cout << "*************************************************" << endl;
cout<<endl<<endl; 

值得一提的是，我无法真正更改“插入”函数或重载运算符的函数头。话虽如此，我将如何组合两个链表？感谢您的帮助。

Answer 1

从您问题中的有限信息来看，我相信这会解决它：

void operator+ (const Word & B)
{
  character *p = B.front;
  while (p != 0)
  {
      Insert(p->symbol);
      p = p->next;
  }
}

如果您发布 cpp 实现文件，也可能是您的主要文件，这将有助于评估此解决方案的正确性。