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[转]C++ STL list的初始化、添加、遍历、插入、…

2019-02-17 01:47:43来源：博客园阅读 ()

list是C++标准模版库(STL,Standard Template Library)中的部分内容。实际上,list容器就是一个双向链表,可以高效地进行插入删除元素。

使用list容器之前必须加上STL的list容器的头文件：#include<list>;

list属于std命名域的内容，因此需要通过命名限定：using std::list;也可以直接使用全局的命名空间方式：using namespace std;

（1）初始化

typedef struct info_s

{

int nNumber;

}info_t;

typedef std::list< info_t > list_t;

定义list的类型

list_t List; //定义一个空的链表

list_t List(count); //建一个含count个默认值是0的元素的链表

list_t List(count, info); //建一个含count个默认值是info的元素的链表

list_t List(List2); //建一个的copy链表

list_t List(List2.begin(),List2.end()); //含区间的元素[First,Last]

（2）添加（添加到末尾）

info_t info;

//Set(info)

List.push_back(info);

将会添加到末尾

(3)遍历

list_t::iterator iter;

for(iter = List.begin(); iter != List.end() ;iter++)

{

std::cout<< iter->nNumber <<std::endl;

}

（4）删除末尾元素

c++的stl list 提供pop_back()函数来删除最后一个元素。

List.pop_back();

（5）删除所有元素

简单粗暴的方法：调用clear()

List.clear();

遍历删除法，一个一个删除，这样的好处是，如果元素有申请内容或者系统资源，我们可以把他释放了，避免资源泄漏。

list_t::iterator iter;

for(iter = List.begin(); iter != List.end() ;)

{

//这里可以做是否内存或者资源的操作

iter = List.erase(iter);

//iter指向了下一个元素

}

（6）插入

iter = List.insert(iter , info);

插入后iter指向新插入的元素。

（7）查找

list_t::iterator iter ;

iter = std::find(List.begin(),List.end(), info);

if(iter != List.end())

{

std::cout<<"find it"<<std::endl;

}

else

{

std::cout<<"not find it"<<std::endl;

}

注意结构体需要重载==运算符

（8）排序

List.sort();

注意，结构体需要重载运算符<

上代码

#include <iostream>
#include <list>
#include <algorithm>

#include <stdlib.h>
#include <string.h>

typedef struct info_s
{
int nNumber;
bool operator==(struct info_s b) const
{
return this->nNumber == b.nNumber;
}

bool operator!=(struct info_s b) const
{
return this->nNumber != b.nNumber;
}

bool operator>=(struct info_s b) const
{
return this->nNumber >= b.nNumber;
}

bool operator<=(struct info_s b) const
{
return this->nNumber <= b.nNumber;
}

bool operator>(struct info_s b) const
{
return this->nNumber > b.nNumber;
}

bool operator<(struct info_s b) const
{
return this->nNumber < b.nNumber;
}

}info_t;

typedef std::list< info_t > list_t;

void append(list_t &List, info_t &info)
{
std::cout<<"***append****"<<std::endl;
List.push_back(info);
}

void for_each(list_t &List)
{
std::cout<<"***for_each****"<<std::endl;
list_t::iterator iter;
for(iter = List.begin(); iter != List.end() ;iter++)
{
std::cout<< iter->nNumber <<std::endl;
}
}

void del_end_info(list_t &List)
{
std::cout<<"***del_end_info****"<<std::endl;
if(! List.empty())
{
List.pop_back();
}
}

void for_each_delete(list_t &List)
{
list_t::iterator iter;
for(iter = List.begin(); iter != List.end() ;)
{
std::cout<< "delete before iter->number:"<<iter->nNumber <<std::endl;
iter = List.erase(iter);
std::cout<< "delete after iter->number:"<< iter->nNumber <<std::endl;
}

}

int insert_one(list_t &List , info_t &info, int iPlace)
{
int i = 0;

std::cout<<"insert_one"<<std::endl;
if(iPlace < 0)
{
std::cout<<"insert_one param error"<<std::endl;
return -1;
}

list_t::iterator iter = List.begin();

while(iter != List.end())
{
//std::cout<<" dump "<< (*iVector)<<std::endl;
if(i == iPlace)
{
iter = List.insert(iter , info); //此时insert的返回值是迭代器，插入成功后iVector指向插入的位置
std::cout<<" insert_one after List point "<<iter->nNumber <<std::endl;
return 0;
}

i++;
++iter;
}

iter = List.insert(List.end() , info);

return 0;
}

void find_one(list_t &List,info_t info )
{

std::cout<<"find_one"<<std::endl;

list_t::iterator iter ;

iter = std::find(List.begin(),List.end(), info);

if(iter != List.end())
{
std::cout<<"find it"<<std::endl;
}
else
{
std::cout<<"not find it"<<std::endl;
}

}

void Sort(list_t & List)
{
std::cout<<"Sort it"<<std::endl;
List.sort();
for_each(List);
}

int main()
{
//初始化
list_t List;
info_t info;
memset(&info, 0, sizeof(info_t));

//添加
info.nNumber = 8;
append(List, info);

info.nNumber = 5;
append(List, info);

info.nNumber = 7;
append(List, info);

info.nNumber = 1;
append(List, info);

info.nNumber = 1;
append(List, info);

info.nNumber = 2;
append(List, info);

info.nNumber = 1;
append(List, info);

//遍历
for_each(List);

//插入
info.nNumber = 80;
insert_one(List,info,3);
for_each(List);
//查找
find_one(List,info);

//排序
Sort(List);

//删除末尾
del_end_info(List);
for_each(List);

std::cout<< " size:"<<List.size()<<std::endl;

//删除所有
// List.clear();
for_each_delete(List);
for_each(List);
std::cout<< " size:"<<List.size()<<std::endl;

return 0;
}