/**********
*
Vector<类型>标识符
Vector<类型>标识符(最大容量)
Vector<类型>标识符(最大容量,初始所有值)
Int i[5]={1,2,3,4,5}
Vector<类型>vi(I,i+2);//得到i索引值为3以后的值
Vector< vector< int> >v; 二维向量//这里最外的<>要有空格。否则在比较旧的编译器下无法通过
clear();//清除容器中所以数据 不会 释放内存
data（）//打印 内存区块
push_back(i); //尾部 install data
pop.back(i) //delete top data
capacity（）// 返回vector的实际存储空间的大小，这个一般大于或等于vector元素个数，注意与size()函数的区别
#include <algorithm> //使用 swap
erase()// 直接用 会产生 野指针问题 配合 remove_if() 使用
vector<int> A; //创建一个空的的容器
vector<int> B(10,100); //创建一个10个元素,每个元素值为100
vector<int> C(B.begin(),B.end()); //使用迭代器,可以取部分元素创建一个新的容器
vector<int> D(C); //复制构造函数,创建一个完全一样的容器
//重载=
vector<int> E;
E = B;
*
*/
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
class car
{
public:
int sp;
};
bool cmp(int a,int b){
return a > b;
}
bool cmpp(car& c)
{
return c.sp >100;
}
int main()
{
vector<int> vec;
vector<int> vc_yq(5,6);
vector<int>:: iterator it;
vector<int>::iterator begin=vec.begin();
vector<int>::iterator end=vec.end();
#if 1 // ;like array[]
for(int i =0;i < 5;++i)
{
vec.push_back(i); //尾部 install data 并没有头插
cout<<vec[i]<<",";
}
cout <<"push_back end "<<endl;
for(int a = 0;a < 5; a++)
{
//vec.pop_back(); //尾删 例如 尾插 0-9 这里 尾删 4-9
cout<<vec[a]<<",";
}
/** iterator use
1)只能读取容器中的元素，而不能修改
**/
cout <<"pop_back"<<endl;
// 遍历
for(it = vec.begin();it != vec.end();++it)
{
//*it =3; error static
cout<< "iterator vec = "<<*it<<endl;
}
for(int i =0 ; i < vec.size();i++) //size_t
{
cout<< " at fu = "<< vec.at(i)<<endl;
}
cout << "=== 成员 交换==="<<endl;
reverse(vec.begin(), vec.end());//交换
for(it = vec.begin();it != vec.end();++it)
{
//*it =3; error static
cout<< "reverse iterator vec = "<<*it<<endl;
}
//从小到大
cout << "===ascend sort 从小到大==="<<endl;
sort(vec.begin(), vec.end());
for(it = vec.begin();it != vec.end();++it)
{
//*it =3; error static
cout<< "sort iterator vec = "<<*it<<endl;
}
//从小到大
cout << "===descend sort 从大到小==="<<endl;
sort(vec.begin(),vec.end(),cmp); // 按降序排序
for(it = vec.begin();it != vec.end();++it)
{
//*it =3; error static
cout<< "descend iterator vec = "<<*it<<endl;
}
cout << "=== vector交换==="<<endl;
cout<< " befor vec memory dir = "<< vec.data()<<endl;
cout<< " befor vc_yq memory dir = "<< vc_yq.data()<<endl;
vec.swap(vc_yq);
cout<< " after vec memory dir = "<< vec.data()<<endl;
cout<< " after vc_yq memory dir = "<< vc_yq.data()<<endl;
for(it = vec.begin();it != vec.end();++it)
{
cout<< "swap iterator vec = "<<*it<<endl;
}
for(it = vc_yq.begin();it != vc_yq.end();++it)
{
cout<< "swap iterator vc_yq = "<<*it<<endl;
}
// 查找
it = find( vec.begin() ,vec.end(),3);
if(it != vec.end())
{
cout<<"find = "<< *it<<endl;
}
// use unique 去重前 先排序 //下面是 去重 两个相同的 元素
cout << "=== unique 使用 ==="<<endl;
int a[]={1,200,3,470,9,4,4,100,100,300,600};
vector<int> unq(a,a+11);
sort(unq.begin(),unq.end());
for(it = unq.begin();it != unq.end();++it)
{
cout<< " sort end = "<<*it<<endl;
}
int t =0,count = 0;
for(auto i = unq.begin();i != unq.end();++i)
{
++t;
//cout<< " *(unq.begin()+1) unique iterator unq = "<<*(unq.begin()+t)<<" *it == "<< *it<< " unq.capacity() = " << unq.capacity()<< " unq.size() = "<<unq.size()<<endl;
cout<< " *i = "<<*i<<" *(i+1) = "<<*(i+1)<< " unq.size() = "<<unq.size() << " t ="<< t <<" count ="<<count<<endl;
if((*i == *(i + 1)) && (t < unq.size()-1))
{
i =unq.erase(i);
cout << "i ="<<*i<<endl;
//i--;
++count;
//cout<< " *(unq.begin()+1) unique iterator unq = "<<*(unq.begin()+t)<<endl;
//cout << "unq.erase(it) "<<*(unq.erase(it))<<endl;
}
//if(count)
//cout<< " erase unique iterator unq = "<<*it<<" *(it+1) = "<<*(it+1)<<endl;
}
#if 0
for(t= 0;t<unq.size();++t)
{
//cout<< " *(unq.begin()+1) unique iterator unq = "<<*(unq.begin()+t)<<" *it == "<< *it<< " unq.capacity() = " << unq.capacity()<< " unq.size() = "<<unq.size()<<endl;
cout<< "unq[t] = "<<unq[t]<<" unq[t+1] = "<<unq[t+1]<<endl;
if((unq[t] == unq[t+1]) && (t < unq.size()-1))
{
//cout<< " *(unq.begin()+1) unique iterator unq = "<<*(unq.begin()+t)<<endl;
++count;
cout << "unq.erase(it) "<<*(unq.erase(unq.begin()+t))<<endl;
}
//if(count)
//cout<< " erase unique iterator unq = "<<*it<<" *(it+1) = "<<*(it+1)<<endl;
}
#endif
cout<< " =============== ===============" <<endl;
//remove_if use
vector<car> cars;
cars.erase( std::remove_if(std::begin(cars), std::end(cars), cmpp), std::end(cars) );
/*
for(it = cars.begin();it != cars.end();++it)
{
cout<< " befor unique iterator unq = "<<*it<<endl;
}
*/
cout<< " =============== ===============" <<endl;
//unique(unq.begin(),unq.end());
for(it = unq.begin();it != unq.end();++it)
{
cout<< " after unique iterator unq = "<<*it<<endl;
}
// 删除问题
/***
if(Iter == v1.end()) //要控制迭代器不能超过整个容器
{
break;
}
**/
// swap memory 释放操作
vec.clear();
cout<< " size vec memory dir = "<< vec.size()<<endl;
//cout<< " clear vec memory dir = "<< vec.clear()<<endl;
cout<< " capacity vec memory dir = "<< vec.capacity()<<endl;
cout << "=== vector release memory==="<<endl;
vector <int>().swap(vc_yq); //和下面的 方式效果相同
{ //花括号 是 为了 退出 tmp 时自动析构
vector <int> tmp;
vec.swap(tmp);
}
cout<< " clear vc_yq memory dir = "<< vc_yq.data()<<endl;
cout<< " clear vec memory dir = "<< vec.data()<<endl;
for(it = vc_yq.begin();it != vc_yq.end();++it)
{
//*it =3; error static
cout<< "swap iterator vc_yq = "<<*it<<endl;
}
#endif
return 0;
}
运行结果：
0,1,2,3,4,push_back end
0,1,2,3,4,pop_back
iterator vec = 0
iterator vec = 1
iterator vec = 2
iterator vec = 3
iterator vec = 4
at fu = 0
at fu = 1
at fu = 2
at fu = 3
at fu = 4
=== 成员 交换===
reverse iterator vec = 4
reverse iterator vec = 3
reverse iterator vec = 2
reverse iterator vec = 1
reverse iterator vec = 0
===ascend sort 从小到大===
sort iterator vec = 0
sort iterator vec = 1
sort iterator vec = 2
sort iterator vec = 3
sort iterator vec = 4
===descend sort 从大到小===
descend iterator vec = 4
descend iterator vec = 3
descend iterator vec = 2
descend iterator vec = 1
descend iterator vec = 0
=== vector交换===
befor vec memory dir = 0x5585dfadd2e0
befor vc_yq memory dir = 0x5585dfadce70
after vec memory dir = 0x5585dfadce70
after vc_yq memory dir = 0x5585dfadd2e0
swap iterator vec = 6
swap iterator vec = 6
swap iterator vec = 6
swap iterator vec = 6
swap iterator vec = 6
swap iterator vc_yq = 4
swap iterator vc_yq = 3
swap iterator vc_yq = 2
swap iterator vc_yq = 1
swap iterator vc_yq = 0
=== unique 使用 ===
sort end = 1
sort end = 3
sort end = 4
sort end = 4
sort end = 9
sort end = 100
sort end = 100
sort end = 200
sort end = 300
sort end = 470
sort end = 600
*i = 1 *(i+1) = 3 unq.size() = 11 t =1 count =0
*i = 3 *(i+1) = 4 unq.size() = 11 t =2 count =0
*i = 4 *(i+1) = 4 unq.size() = 11 t =3 count =0
i =4
*i = 9 *(i+1) = 100 unq.size() = 10 t =4 count =1
*i = 100 *(i+1) = 100 unq.size() = 10 t =5 count =1
i =100
*i = 200 *(i+1) = 300 unq.size() = 9 t =6 count =2
*i = 300 *(i+1) = 470 unq.size() = 9 t =7 count =2
*i = 470 *(i+1) = 600 unq.size() = 9 t =8 count =2
*i = 600 *(i+1) = 600 unq.size() = 9 t =9 count =2
=============== ===============
befor unique iterator unq = 10
=============== ===============
after unique iterator unq = 1
after unique iterator unq = 3
after unique iterator unq = 4
after unique iterator unq = 9
after unique iterator unq = 100
after unique iterator unq = 200
after unique iterator unq = 300
after unique iterator unq = 470
after unique iterator unq = 600
size vec memory dir = 0
capacity vec memory dir = 5
=== vector release memory===
clear vc_yq memory dir = 0
clear vec memory dir = 0
