C++ STL学习之list

LIST 是一个双向链表。

因为本人的C++的编程时间有限，目前还没怎么用到list，在数据结构中，list是一个比较重要的。

首先复习一下什么是双向链表。双向链表是一种每个节点都有两个指针，分别直接的指向了直接前驱和直接后驱。这种方式对访问一个节点的前后都是十分方便快捷的。向前向后搜索的时间都是为常量时间。

并且在链表的头和尾部插入元素的时间都是常量时间。

List有以下优点:

• Efficient insertion and removal of elements anywhere in the container (constant time).
• Efficient moving elements and block of elements within the container or even between different containers (constant time).
• Iterating over the elements in forward or reverse order (linear time).

C++ stl中list提供了两个参数

template < class T, class Allocator = allocator<T> > class list;

Where the template parameters have the following meanings:

• T: 数据类型
• Allocator: Type of the allocator object used to define the storage allocation model. By default, theallocator class template for type T is used, which defines the simplest memory allocation model and is value-independent.

In the reference for the list member functions, these same names are assumed for the template parameters.

Public base classes

None.

list成员函数 ，描述就不翻译了，保持原汁原味。

Member Where defined Description

value_type	Container	The type of object, T, stored in the list.
pointer	Container	Pointer to T.
reference	Container	Reference to T
const_reference	Container	Const reference to T
size_type	Container	An unsigned integral type.
difference_type	Container	A signed integral type.
iterator	Container	Iterator used to iterate through a list.
const_iterator	Container	Const iterator used to iterate through a list.
reverse_iterator	Reversible Container	Iterator used to iterate backwards through a list.
const_reverse_iterator	Reversible Container	Const iterator used to iterate backwards through a list.
iterator begin()	Container	Returns an iterator pointing to the beginning of the list.
iterator end()	Container	Returns an iterator pointing to the end of the list.
const_iterator begin() const	Container	Returns a const_iterator pointing to the beginning of thelist.
const_iterator end() const	Container	Returns a const_iterator pointing to the end of the list.
reverse_iterator rbegin()	Reversible Container	Returns a reverse_iterator pointing to the beginning of the reversed list.
reverse_iterator rend()	Reversible Container	Returns a reverse_iterator pointing to the end of the reversed list.
const_reverse_iterator rbegin() const	Reversible Container	Returns a const_reverse_iterator pointing to the beginning of the reversed list.
const_reverse_iterator rend() const	Reversible Container	Returns a const_reverse_iterator pointing to the end of the reversed list.
size_type size() const	Container	Returns the size of the list. Note: you should not assume that this function is constant time. It is permitted to beO(N), where N is the number of elements in the list. If you wish to test whether alist is empty, you should write L.empty() rather than L.size() == 0.
size_type max_size() const	Container	Returns the largest possible size of the list.
bool empty() const	Container	true if the list's size is 0.
list()	Container	Creates an empty list.
list(size_type n)	Sequence	Creates a list with n elements, each of which is a copy ofT().
list(size_type n, const T& t)	Sequence	Creates a list with n copies of t.
list(const list&)	Container	The copy constructor.
template <class InputIterator> list(InputIterator f, InputIterator l) [2]	Sequence	Creates a list with a copy of a range.
~list()	Container	The destructor.
list& operator=(const list&)	Container	The assignment operator
reference front()	Front Insertion Sequence	Returns the first element.
const_reference front() const	Front Insertion Sequence	Returns the first element.
reference back()	Sequence	Returns the last element.
const_reference back() const	Back Insertion Sequence	Returns the last element.
void push_front(const T&)	Front Insertion Sequence	Inserts a new element at the beginning.
void push_back(const T&)	Back Insertion Sequence	Inserts a new element at the end.
void pop_front()	Front Insertion Sequence	Removes the first element.
void pop_back()	Back Insertion Sequence	Removes the last element.
void swap(list&)	Container	Swaps the contents of two lists.
iterator insert(iterator pos, const T& x)	Sequence	Inserts x before pos.
template <class InputIterator> void insert(iterator pos, InputIterator f, InputIterator l) [2]	Sequence	Inserts the range [f, l) before pos.
void insert(iterator pos, size_type n, const T& x)	Sequence	Inserts n copies of x before pos.
iterator erase(iterator pos)	Sequence	Erases the element at position pos.
iterator erase(iterator first, iterator last)	Sequence	Erases the range [first, last)
void clear()	Sequence	Erases all of the elements.
void resize(n, t = T())	Sequence	Inserts or erases elements at the end such that the size becomesn.
void splice(iterator pos, list& L)	list	See below.
void splice(iterator pos, list& L, iterator i)	list	See below.
void splice(iterator pos, list& L, iterator f, iterator l)	list	See below.
void remove(const T& value)	list	See below.
void unique()	list	See below.
void merge(list& L)	list	See below.
void sort()	list	See below.
bool operator==(const list&, const list&)	Forward Container	Tests two lists for equality. This is a global function, not a member function.
bool operator<(const list&, const list&)	Forward Container	Lexicographical comparison. This is a global function, not a member function.

在这里，着重强调一下list的构造函数，内部形式如下

explicit list ( const Allocator& = Allocator() );
explicit list ( size_type n, const T& value = T(), const Allocator& = Allocator() );
template < class InputIterator >
         list ( InputIterator first, InputIterator last, const Allocator& = Allocator() );
list ( const list<T,Allocator>& x );

下面一个例子：

// list.cpp : 定义控制台应用程序的入口点。
// by wallwind at sunrise 2011/10/20

#include "stdafx.h"
#include <list>
#include <iostream>
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
	list<int> mylist1;
	list<int> mylist2(4,10);
	list<int> mylist3(mylist2.begin(),mylist2.end());
	list<int> mylist4(mylist3);
	
	int myints[]={1,3,4,5,6};
	list<int> mylist5(myints,myints+sizeof(myints)/sizeof(int));

	for (list<int>::iterator it=mylist5.begin();it!=mylist5.end();it++)
	{
		cout<<*it<<" ";
	}
	cout<<endl;		cout<<"mylist5 size: "<<mylist5.size()<<endl;
	
	for (int i=1;i<=4;i++)
	{
		mylist1.push_back(i);
	}
	mylist2.clear();
	for (int i=1; i<=3; i++)
		mylist2.push_back(i*10);   
	list<int> ::iterator it1=mylist1.begin();
	++it1;
	mylist1.splice(it1,mylist2);//mylist1: 1 10 20 30 2 3 4
								//mylist2 (empty)
								//"it" still points to 2 (the 5th element)
	mylist2.splice(mylist2.begin(),mylist1,it1);// mylist1: 1 10 20 30 3 4
												// mylist2: 2
												// "it" is now invalid.
	it1=mylist1.begin();
	advance(it1,3);   //it points to "30"
	
	return 0;
}

今天到此结束，准备准备打算自己用C++实现数据结构敬请期待

更多内容：http://blog.csdn.net/wallwind