我創建了一個容器列表的小實現,它基於測試main()
執行某些功能。我的列表<T>實施有什麼問題?
我想添加一些額外的功能。主要是一個operator[]
和一個reverse()
函數,它向後顯示列表中的數字。
這是我的代碼,每一句評論都是昨天添加的。
#include <iostream>
#include <algorithm>
using namespace std;
template <class T> class Link;
template <class T> class List_iterator;
template <class T> class Reverse_iterator;
template <class T>
class List
{
public:
typedef List_iterator<T> iterator;
List();
List(const List<T> & l);
~List();
bool empty() const;
unsigned int size() const;
T & back() const;
T & front() const;
void push_front(const T & x);
void push_back(const T & x);
void pop_front();
void pop_back();
iterator begin() const;
iterator end() const;
iterator rbegin() const;//REVERSE BEGIN
iterator rend() const; //REVERSE END
void insert(iterator pos, const T & x);
void erase(iterator & pos);
List<T> & operator=(const List<T> & l);
List<T> & operator[] (unsigned int x);//OPERATOR []
iterator reverse() const; //REVERSE
protected:
Link<T> * first_link;
Link<T> * last_link;
unsigned int my_size;
};
template <class T>
List<T>::List()
{
first_link = 0;
last_link = 0;
my_size = 0;
}
template <class T>
List<T>::List(const List & l)
{
first_link = 0;
last_link = 0;
my_size = 0;
for (Link<T> * current = l.first_link; current != 0; current = current -> next_link)
push_back(current -> value);
}
template <class T>
typename List<T>::iterator List<T>::begin() const
{
return iterator(first_link);
}
template <class T>
typename List<T>::iterator List<T>::end() const
{
return iterator (last_link);
}
//RBEGIN
template <class T>
typename List<T>::iterator List<T>::rbegin() const
{
return iterator (last_link);
}
//REND
template <class T>
typename List<T>::iterator List<T>::rend() const
{
return iterator(first_link);
}
template <class T>
class Link
{
private:
Link(const T & x): value(x), next_link(0), prev_link(0) {}
T value;
Link<T> * next_link;
Link<T> * prev_link;
friend class List<T>;
friend class List_iterator<T>;
};
template <class T> class List_iterator
{
public:
typedef List_iterator<T> iterator;
List_iterator(Link<T> * source_link): current_link(source_link) { }
List_iterator(): current_link(0) { }
List_iterator(List_iterator<T> * source_iterator): current_link(source_iterator.current_link) { }
T & operator*();
iterator & operator=(const iterator & rhs);
bool operator==(const iterator & rhs) const;
bool operator!=(const iterator & rhs) const;
iterator & operator++();
iterator operator++(int);
iterator & operator--();
iterator operator--(int);
protected:
Link<T> * current_link;
friend class List<T>;
};
template <class T>
T & List_iterator<T>::operator*()
{
return current_link -> value;
}
template <class T>
List_iterator<T> List_iterator<T>::operator++(int)
{
}
template <class T>
List_iterator<T> & List_iterator<T>::operator--()
{
current_link = current_link -> prev_link;
return * this;
}
template <class T>
List_iterator<T> & List_iterator<T>::operator=(const iterator & rhs)
{
///???
}
template <class T>
List_iterator<T> List_iterator<T>::operator--(int)
{
}
template <class T>
List_iterator<T> & List_iterator<T>::operator++()
{
current_link = current_link -> next_link;
return *this;
}
template <class T>
void List<T>::push_back(const T & x)
{
Link<T> * new_link = new Link<T> (x);
if (first_link == 0)
first_link = last_link = new_link;
else
{
new_link->prev_link = last_link;
last_link->next_link = new_link;
last_link = new_link;
}
my_size++;
}
template <class T>
List <T>::~List()
{
Link <T> * first = first_link;
while (first != 0)
{
Link <T> * next = first->next_link;
delete first;
first = next;
}
}
template<class T>
bool List_iterator<T>::operator==(const iterator & rhs) const
{
return (this->current_link == rhs.current_link);
}
template <class T>
bool List_iterator<T>::operator!=(const iterator & rhs) const
{
return !(*this == rhs);
}
//REVERSE ITERATOR
template <class T> class Reverse_iterator
{
public:
typedef Reverse_iterator<T> riterator;
Reverse_iterator(Link<T> * source_link): current_link(source_link) { }
Reverse_iterator(): current_link(0) { }
Reverse_iterator(List_iterator<T> * source_iterator): current_link(source_iterator.current_link) { }
T & operator*();
riterator & operator=(const riterator & rhs);
bool operator==(const riterator & rhs) const;
bool operator!=(const riterator & rhs) const;
riterator & operator++();
riterator operator++(int);
riterator & operator--();
riterator operator--(int);
protected:
Link<T> * current_link;
friend class List<T>;
};
template <class T>
T & Reverse_iterator<T>::operator*()
{
return current_link -> value;
}
template <class T>
Reverse_iterator<T> Reverse_iterator<T>::operator++(int)
{
}
template <class T>
Reverse_iterator<T> & Reverse_iterator<T>::operator--()
{
current_link = current_link -> next_link;
return * this;
}
template <class T>
Reverse_iterator<T> & Reverse_iterator<T>::operator=(const riterator & rhs)
{
//???
}
template <class T>
Reverse_iterator<T> Reverse_iterator<T>::operator--(int)
{
}
template<class T>
bool Reverse_iterator<T>::operator==(const riterator & rhs) const
{
return (this->current_link == rhs.current_link);
}
template <class T>
bool Reverse_iterator<T>::operator!=(const riterator & rhs) const
{
return !(*this == rhs);
}
//REVERSE FUNCTION
template <class T>
List_iterator<T> List<T>::reverse() const
{
iterator i, j;
i = begin();
j = end();
for(; i != j; j++, j--)
{
T value = *j;
*j = *i;
*i = value;
}
}
//OPERATOR []
template <class T>
List<T> & List<T>:: operator[] (unsigned int x)
{
Link<T> * current = first_link;
for(int i = 0; i != x && i < my_size; i++)
current = current -> next_link;
return current -> value;
delete current;
}
//REVERSE ITERATOR OPERATOR ++()
template <class T>
Reverse_iterator<T> & Reverse_iterator<T>::operator++()
{
current_link = current_link -> prev_link;
return *this;
}
int main()
{
List<int> l;
l.push_back(44);
l.push_back(33);
l.push_back(11);
l.push_back(22);
List<int> m(l);
cout << "This is the original list" << endl;
List<int>::iterator original(m.begin());
while (original != m.end()) {
cout << *original << endl;
++original;
//cout << l[4]; //Not working
//m.reverse();
//cout << m;//Also Not working
}
}
我在尋求幫助:
- 寫我
operator=()
功能,這是目前空白。 - 瞭解爲什麼
main()
中的最後幾行不能正常工作(我知道它們已被註釋掉),請查看我的operator[]
定義和我的reverse()
函數。
在此先感謝。
這裏有太多的代碼。請只發布您有疑問的部分。另外,試着讓你的問題更具體,也許考慮把它分成幾個問題。 – 2011-03-16 14:50:04
基本上,只是想知道是否有人可以幫助145行上的[]運算符,因爲我的實現目前還沒有工作,並想知道是否有人可以查看我的反向函數272行,並告訴我爲什麼它會在終端中返回一個錯誤,我雖然那個功能很紮實,我不知道要改變什麼。對不起,這個問題太長了。 – mikhailovich 2011-03-16 15:01:12
查看我的答案,下面是對運營商的幫助[] – razlebe 2011-03-16 15:17:42