我几周来一直在与Pointers和坦率的C ++斗争。我有一个放弃的学校项目（截止日期已经过去）。尽管我无法将其转换为练习，但我仍然坚持使用我的清晰方法，但我可能还有其他方法可以做到这一点。
.h文件
using namespace std;
template < typename T > // Forward declaration of the SimpList class
class SimpList;
//--------------------------------------------------------------------
//
// Definition of class Node<T>
//
//--------------------------------------------------------------------
template < typename T >
class Node // Node class for the SimpList class
{
private:
// Constructors
Node () { next = 0; } // default constructor
// Complete the definition inline
Node ( const T &initItem, Node<T> *ptr ) {
value=initItem;
next=ptr;
}
// Data members
T value; // Node data item
Node *next; // Pointer to the next node
friend class SimpList<T>;
};
//--------------------------------------------------------------------
//
// Definition of class SimpList<T>
//
//--------------------------------------------------------------------
template < typename T >
class SimpList
{
public:
// Constructor (add your code inline)
SimpList ()
{
head = &PHONY;
length=0;
// complete the data member intialization
}
// Destructor (add your code inline)
~SimpList () { clear();}
// List manipulation operations
void insert ( const T &newitem ); // insert a data item
bool remove ( T &item ); // remove data item
bool find ( T &item ) const; // find data item
void clear (); // empty the list
// (add your code inline)
bool isEmpty () const {
if (length == 0)
{
return true;
}
else
{
return false;
}
}
// length accessor method (add your code inline)
int size () const { return length; }
// print the list items
void print () const;
private: // data members
Node<T> PHONY ; // empty node that anchors the list
Node<T> *head; // pointer to the beginning of the list
int length; // length of list
};
//--------------------------------------------------------------------
//
// Implementation section
//
//--------------------------------------------------------------------
template < typename T >
void SimpList<T>::print() const
{
if (length == 0)
{
cout << "List is empty." << endl;
return;
}
Node<T> *ptr=head;
while (ptr != NULL)
{
cout << ptr->value << " ";
ptr = ptr->next;
}
cout << endl;
}
template <typename T>
void SimpList<T>::insert ( const T &newitem )
{
Node<T> *p = new Node<T>;
p->value = newitem;
p->next = head;
head = p;
length++;
}
template <typename T>
void SimpList<T>::clear ()
{
Node<T> *p = head->next;
while(p != NULL)
{
head=head->next;
delete p;
}
length = 0;
}
template <typename T>
bool SimpList<T>::find ( T &item ) const
{
Node<T> *p;
for(p=head; p!=NULL; p=p->next)
if(p->value==item) break;
if(p!=NULL)
{
item=p->value;
return true;
}
else
{
return false;
}
}
template <typename T>
bool SimpList<T>::remove ( T &item )
{
Node<T> *p,*c;
for(c=head; c!=NULL;p=c,c=c->next)
if(c->value==item) break;
if(c!=NULL)
{
item=c->value;
p->next=c->next;
delete c;
length --;
for(c=head;c!=NULL;c=c->next)
cout<<c->value<<" ";
return true;
}
else
return false;
}
.cpp文件在这里。
#include <iostream>
#include <string>
#include "simpList.h"
int main()
{
SimpList<int> intList; // (empty) list of integers
cout << "Let's build a sorted list of integers." << endl;
cout << endl << "Uninitialized List: ";
intList.print();
cout << endl << "Length: " << intList.size() << endl;
int intData[] = { 5, 3, -2, 7, 9, -8, 1, -4 };
for (int i=0; i<8; i++){
intList.insert( intData[i] );
}
cout << endl << "After inserting 8 integers: ";
intList.print();
cout << endl << "Length: " << intList.size() << endl;
cout << endl << "--- Testing the \"find\" method:" << endl;
int t = 5;
bool ret = intList.find(t);
cout << endl << t << " is in the list: "
<< (ret ? "true" : "false") << endl;
t = 6;
ret = intList.find(t);
cout << endl << t << " is in the list: "
<< (ret ? "true" : "false") << endl;
cout << endl << "--- Testing the \"remove\" method:" << endl;
t = 5;
ret = intList.remove(t);
cout << endl << t << " has been removed: "
<< (ret ? "true" : "false") << endl;
cout << endl << "Remaining list: ";
intList.print();
cout << endl << "Length: " << intList.size() << endl;
cout << endl << "--- Testing the \"clear\" method:" << endl << endl;
intList.clear();
intList.print();
cout << endl << "Length: " << intList.size() << endl;
cout << endl << "--- Testing the \"isEmpty\" predicate:" << endl;
cout << endl << "The integer list is now empty: "
<< (intList.isEmpty()? "true" : "false") << endl << endl;
cout << "Now, let's build a sorted list of strings." << endl;
string strData[] = { "Maria", "Ann", "Emily", "Vivian",
"Beth", "Carla", "Susan" };
SimpList<string> strList;
for (int i=0; i<7; i++){
strList.insert( strData[i] );
}
cout << endl << "After inserting 7 names:" << endl;
strList.print();
cout << endl << "Length: " << strList.size() << endl;
cout << endl << "--- Testing the \"remove\" method:" << endl;
cout << endl << "Bye Carla!" << endl;
string str = "Carla";
ret = strList.remove(str);
cout << endl << str << " has been removed: "
<< (ret ? "true" : "false") << endl;
cout << endl << "Remaining list:" << endl;
strList.print();
cout << endl << "Length: " << strList.size() << endl;
cout << endl << "--- Testing the \"insert\" method:" << endl;
cout << endl << "Bienvenue Pauline!" << endl;
string nom = "Pauline";
strList.insert(nom);
cout << endl << "Extended list:" << endl;
strList.print();
cout << endl << "Length: " << strList.size() << endl;
cout << endl << "--- Auf Wiedersehen!" << endl;`enter code here`
cout << endl << "End of \"main()\"." << endl
<< "At this point, the destructor is called." << endl;
system("PAUSE");}
固定
当打印出列表中的项目时，它会打印所有项目以及-858993460，并且我已经用尽了解如何修复它。
我非常感谢你们的帮助或者指向正确的方向。
答案 0 :(得分：0)
通过函数的逻辑思考。将其绘制成纸上的方框，并计算出需要移动和删除指针的顺序
考虑删除链表的这个序列。
while(there is still an item left in the list) {
take a copy of the existing head pointer
move the head pointer to the next item
delete the old head using the copy of the head pointer you took before changing it
}
set length to zero
请注意，在普通列表中，当列表为空时，头指针应设置为零，并且“下一个”指针在列表的最后一项上将为零。
答案 1 :(得分：0)
在明确的功能中尝试这个
while(head!=NULL)
。 {node * p = head; 。头=头戴式＆gt;接着， 。删除p 。 }
并确保最初将head设置为null。否则在上次迭代过程中会占用一些垃圾值。