Question

我创建了一个执行多个功能的链接列表程序。我写了一个函数来销毁以“top”作为参数的列表。我最终在析构函数中使用了这个函数。我真的可以测试一下吗？

这是我缩短的Family.h：

#ifndef FAMILY_H
#define FAMILY_H

#include<string>
using namespace std;

#include "Child.h"
#include "Wife.h"
#include "Husband.h"

class Family
{
 protected:
  HusPtr top;
  void Destroy(HusPtr& top); //I know in order to access this in the Main, I'd have to make 
                             //this Public.  But I'd have to create a local pointer named top.
                             //Because the local pointer points to nothing, I get a segmentation
                             //fault.
 public:
  Family();
  Family(HusPtr& h);
  Family(const Family& source);
  ~Family();
 };
#endif

这是我的Family.cpp中的Destroy函数：

void Family::Destroy(HusPtr& top)
{
  HusPtr curr = top;
  WifePtr w = curr->myWife;

  while(curr != NULL)
    {
      if(curr->myWife != NULL)
        {
          while(w->myChildren != NULL)
            {
              ChildPtr c = w->myChildren;
              ChildPtr cNext = c->mySibling;
              w->myChildren = cNext;
              delete c;
            }
          curr->myWife = NULL;
          delete w;
        }
      HusPtr next = curr;
      curr = next->nextFamily;
      delete next;
      top = curr;
    }
}

我的Main.cpp：

using namespace std;

#include "Family.h"
HusPtr top; //points to nothing.

int main()
{
  Family F1;
  F1.ProcessTransaction("transaction.txt");
  F1.Destroy(top);// gives a segmentation fault...likely due to the fact that top points to nothing.
}

Wife.h：

#ifndef HUSBAND_H
#define HUSBAND_H

#include<string>
using namespace std;

#include "Person.h"

class Husband;
typedef Husband* HusPtr;
class Wife;
typedef Wife* WifePtr;

class Husband:public Person
{
  friend class Wife;
  friend class Family;

 protected:
  HusPtr nextFamily;
  WifePtr myWife;

 public:
  Husband();
  Husband(long hSSN, string hFirst, string hLast);
  void Print() const;
};

#endif

Wife.h：

#ifndef WIFE_H
#define WIFE_H

#include<string>
using namespace std;

#include "Person.h"
#include "Child.h"

class Child;
typedef Child* ChildPtr;

class Wife:public Person
{
  friend class Family;

 protected:
  ChildPtr myChildren;

 public:
  Wife();
  Wife(long wSSN, string wFirst, string wLast);
  void Print() const;
};


#endif

Child.h：

#ifndef CHILD_H
#define CHILD_H

#include<string>
using namespace std;

#include "Person.h"

class Child;
typedef Child* ChildPtr;

class Child:public Person
{
  friend class Family;

 protected:
  ChildPtr mySibling;

 public:
  Child();
  Child(long cSSN, string cFirst, string cLast);
  void Print() const;
};

#endif

这不是此任务中所需的功能，但无论如何我决定实施它。一切都很好，应该可以工作，但我真的认为我收到的分段错误是因为我传递了一个在Main.cpp中创建的指针，它没有指向任何地方。我是对的吗？

Answer 1

在删除w后的第二次迭代中，您不会再次分配它。但是你试着再次访问它的孩子。所以它会崩溃。

in while循环

第一次迭代 ... 删除w;

第二次迭代

W-＆GT;儿童;程序将崩溃。

是否可以测试链接列表的销毁功能？

1 个答案: