C++STL之list

目录

1.list的使用

2.list iterator的使用 

3.list的常用接口 

4.list的迭代器失效 

5.list的模拟实现 

6.list的反向迭代器 

7.list与vector的对比

2.list iterator的使用 

3.list的常用接口 

4.list的迭代器失效 

void TestListIterator1()
{
int array[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
list<int> l(array, array+sizeof(array)/sizeof(array[0]));
auto it = l.begin();
while (it != l.end())
{
// erase()函数执行后，it所指向的节点已被删除，因此it无效，在下一次使用it时，必须先给
其赋值
l.erase(it);
++it;
}
}
// 改正
void TestListIterator()
{
int array[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
list<int> l(array, array+sizeof(array)/sizeof(array[0]));
auto it = l.begin();
while (it != l.end())
{
l.erase(it++); // it = l.erase(it);
}
}

5.list的模拟实现 

#pragma once
#include<iostream>namespace bit
{template<class T>struct list_node{T _data;list_node<T>* _next;list_node<T>* _prev;list_node(const T& data = T()):_data(data), _next(nullptr), _prev(nullptr){}};// const_iteratortemplate<class T>struct list_iterator{typedef list_node<T> Node;typedef list_iterator<T> Self;Node* _node;list_iterator(Node* node):_node(node){}T& operator*(){return _node->_data;}Self& operator++(){_node = _node->_next;return *this;}Self& operator--(){_node = _node->_prev;return *this;}bool operator!=(const Self& s) const{return _node != s._node;}bool operator==(const Self& s) const{return _node == s._node;}};template<class T>class list{typedef list_node<T> Node;public:typedef list_iterator<T> iterator;iterator begin(){/*	iterator it(_head->_next);return it;*///return iterator(_head->_next);return _head->_next;}iterator end(){return _head;}list(){_head = new Node;_head->_next = _head;_head->_prev = _head;_size = 0;}void push_back(const T& x){/*Node* newnode = new Node(x);Node* tail = _head->_prev;tail->_next = newnode;newnode->_prev = tail;newnode->_next = _head;_head->_prev = newnode;++_size;*/insert(end(), x);}void push_front(const T& x){insert(begin(), x);}void insert(iterator pos, const T& x){Node* cur = pos._node;Node* prev = cur->_prev;Node* newnode = new Node(x);// prev newnode curnewnode->_next = cur;cur->_prev = newnode;newnode->_prev = prev;prev->_next = newnode;++_size;}void pop_back(){erase(--end());}void pop_front(){erase(begin());}void erase(iterator pos){assert(pos != end());Node* prev = pos._node->_prev;Node* next = pos._node->_next;prev->_next = next;next->_prev = prev;delete pos._node;--_size;}size_t size() const{return _size;}bool empty() const{return _size == 0;}private:Node* _head;size_t _size;};void test_list1(){list<int> lt;lt.push_back(1);lt.push_back(2);lt.push_back(3);lt.push_back(4);list<int>::iterator it = lt.begin();while (it != lt.end()){std::cout << *it << " ";++it;}std::cout << std::endl;}
}

6.list的反向迭代器 

template<class Iterator>
class ReverseListIterator
{
// 注意：此处typename的作用是明确告诉编译器，Ref是Iterator类中的类型，而不是静态
成员变量
// 否则编译器编译时就不知道Ref是Iterator中的类型还是静态成员变量
// 因为静态成员变量也是按照 类名::静态成员变量名 的方式访问的
public:
typedef typename Iterator::Ref Ref;
typedef typename Iterator::Ptr Ptr;
typedef ReverseListIterator<Iterator> Self;
public:
//
// 构造
ReverseListIterator(Iterator it): _it(it){}
//
// 具有指针类似行为
Ref operator*(){
Iterator temp(_it);
--temp;
return *temp;
}
Ptr operator->(){ return &(operator*());}
//
// 迭代器支持移动
Self& operator++(){
--_it;
return *this;
}
Self operator++(int){
Self temp(*this);
--_it;
return temp;
}
Self& operator--(){
++_it;
return *this;
}
Self operator--(int)
{
Self temp(*this);
++_it;
return temp;
}
// 迭代器支持比较
bool operator!=(const Self& l)const{ return _it != l._it;}
bool operator==(const Self& l)const{ return _it != l._it;}
Iterator _it;
};