标签：
Vector是一个称为向量的顺序容器（不明白顺序容器与关联容器的可以Google）。
1. 动态（相当于一个动态数组）；
2. 可用于存放各种数据结构（内置的，自定义的，当然也可以是vector）（当是vector时注意申明格式eg：vector<vector<Information>>与vector< vector<Information> >，前者错误，后者正确,两个‘>’要有空格）；
3. 支持对vector元素的随即访问；
4. 以拷贝的方式用一个vector初始化另一个vector时，两个vector类型要一致；
5. 每一个vector的容量要比其大小相对较大或相等（eg：vec.capacity()>=vec.size()）。
Vec.begin();//向量中的首个元素的地址，加n后表示第n个元素的地址（eg：vec.begin()+3）； Vec.end();//向量中最后一个元素的地址； Vec.rbegin();//指向反序后的向量首元素； Vec.rend();//指向反序后的尾元素； vec.front();//返回vector中的第一元素的值 vec.back();//返回vector中的最后一个元素的值 Vec.insert();//向向量中任意位置插入一个或多个元素； Vec.clear();//向量清空; Vec.push_back();//将元素压入向量的尾部； //Vec.push_front();//vector中无此用法（用了之后会造成元素的迁移，与vector设计的初衷相违背）； Vec.erase();//删除向量中任意一个或一段元素； Vec.pop_back();//删除向量中最后一个元素； Vec.size();//返回向量的大小 Vec.capacity();//返回向量容量的大小 Vec.empty();//向量为空返回false，不为空返回true； Vec1.swap(vec2);//交换向量vec1和向量vec2；
示例一：//vector元素为简单的元素，进行简单地操作
#include<iostream>
#include<iomanip>
#include<vector>
#include<string>
using namespace std;
template <typename T>//一个函数末班，用向量表示函数
void display(vector<T>&vec)
{
static int n=1;//设置一个静态变量，用来标记每次输出
cout<<n++<<‘.‘<<endl;
cout<<"the size of the vec is "<<vec.size()<<endl;
cout<<"the capacity of the vec is"<<vec.capacity()<<endl;
if(!vec.empty())
{
cout<<"the contents are:"<<endl;
for(int i=0;i<vec.size();i++)
{
cout<<setw(10)<<vec[i];
}
cout<<endl<<endl;
}
else
cout<<"this is a empty vector"<<endl<<endl;
}
const int size=5;
int main()
{
string str[size]={"love","you","my","c++","language"};
vector<string>vec1;
vec1.insert(vec1.begin(),str,str+size);//从vec1.begin()(此时等于vec1.end())处插入所有str当中的字符
display(vec1);
cout<<vec1.front()<<endl;//返回第一个元素的值
cout<<vec1.front()+" VB.NET"<<endl;
cout<<vec1.back()<<endl;//返回最后一个元素的值
cout<<vec1.back()+" VB.NET"<<endl;
cout<<*(vec1.begin()+1)<<endl;//用cout流对象输出vecotor的元素
cout<<*(vec1.rbegin()+1)+" c#"<<endl;
cout<<vec1[1]<<endl<<endl;//用下标法输出vecotor元素
vec1.clear();//清空向量vec1
display(vec1);
vec1.insert(vec1.begin(),str+2,str+size-1);//可以插入任意个元素（此处为2个）
display(vec1);
vec1.insert(vec1.begin()+1,3,"java");//从vec1.begin()+1处插入3个“Java”字符串
display(vec1);
vec1.insert(vec1.begin()+3,3,str[2]);//从vec1.begin()+3处插入3个str[2]字符串
display(vec1);
vector <string>vec2(vec1);//调用拷贝构造函数，以vec1初始化vec2
display(vec2);
vec2.clear();
vec2.insert(vec2.end(),vec1.begin(),vec1.end());
display(vec2);
vec2.erase(vec2.begin()+3,vec2.begin()+6);//删除vec2.begin()+3到vec2.begin()+6之间的字符串
display(vec2);
for(int i=0;i<5;i++)
{
vec2.pop_back();//删除最后一个字符串
display(vec2);
}
return 0;
}
示例二：vector元素为struct
#include<iostream>
#include<string>
#include<vector>
#include<iomanip>
using namespace std;
const int n=6;
struct Information
{
string studentName;
string studentSex;
double studentRank;
friend ostream &operator<<(ostream& out,Information &p);
friend istream &operator>>(istream& in,vector<Information>&p);
};
istream &operator>>(istream& in,vector<Information>&p)//重载输入用算符，不是此blog重点，在主函数中未使用
{
for(int i=0;i<n;i++)
in>>p[i].studentName>>p[i].studentSex>>p[i].studentRank;
return in;
}
ostream &operator<<(ostream& out,vector<Information>&p)//重载输出用算符，可以看到有与display()函数同样的效果
{
for(int i=0;i<n;i++)
out<<"name: "<<setw(10)<<p[i].studentName<<" sex: "<<setw(2)<<p[i].studentSex<<" rank: "<<setw(5)<<p[i].studentRank<<endl;
return out;
}
void display(vector<Information>&Student)//显示排名情况
{
if(!(Student.empty()))
{
for(int i=0;i<Student.size();i++)
{
cout<<"name: "<<setw(10)<<Student[i].studentName<<" sex: "<<setw(5)<<Student[i].studentSex<<" rank: "<<setw(5)<<Student[i].studentRank<<endl;
}
}
else
cout<<"this is a empty vector"<<endl;
}
int main()
{
string name[n]={"ZhangSan","liSi","WangMaZi","XiaoMing","XiaoHua","XiaoZhang"};
vector<string>Name;
vector<string>Sex(n,"\0");
vector<int>Rank(n,0);//初始化一个大小为n，元素都为零的向量
Name.insert(Name.begin(),name,name+n);
for(int i=0;i<n;i++)
{
cout<<"Please input "<<Name[i]<<"‘s sex: ";
cin>>Sex[i];
cout<<"Please input "<<Name[i]<<"‘s rank(0~100): ";
cin>>Rank[i];//用流对象cin向向量赋值
}
vector<Information>Student1;
//cin>>Student;
for(int i=0;i<n;i++)
{
Information temp;
temp.studentName=Name[i];
temp.studentSex=Sex[i];
temp.studentRank=Rank[i];
Student1.push_back(temp);
}
cout<<"the rank of student1 is: "<<endl;
display(Student1);
cout<<endl<<Student1;
vector<Information>Student2(Student1);
cout<<endl<<"the rank of student2 set is: "<<endl;
display(Student2);
vector<Information>Student3(Student2.begin(),Student2.end()-3);
cout<<endl<<"the size of student3 is: "<<Student3.size()<<endl;
Student3.swap(Student2);
cout<<"the size of student2 is: "<<Student2.size()<<endl;
cout<<"the size of student3 is: "<<Student3.size()<<endl;
Student3.pop_back();
cout<<"Student3‘s size is: "<<setw(5)<<Student3.size()<<endl;
Student3.erase(Student3.begin());
cout<<"Student3‘s size is: "<<setw(5)<<Student3.size()<<endl;
display(Student3);
return 0;
}
示例三：vector元素为vector
#include<iostream>
#include<string>
#include<vector>
#include<iomanip>
#include<windows.h>
using namespace std;
const int n=6;
static int N1=1;
static int N2=N1;
struct Information
{
string studentName;
string studentSex;
double studentRank;
friend ostream &operator<<(ostream& out,Information &p);
friend istream &operator>>(istream& in,vector<Information>&p);
};
ostream &operator<<(ostream& out,vector<Information>&p)//重载输出用算符，可以看到有与display()函数同样的效果
{
cout<<‘(‘<<N1++<<‘)‘<<endl;
for(int i=0;i<n;i++)
out<<"name: "<<setw(10)<<p[i].studentName<<" sex: "<<setw(5)<<p[i].studentSex<<" rank: "<<setw(5)<<p[i].studentRank<<endl;
return out;
}
ostream &operator<<(ostream& out,vector< vector<Information> >&p)
{
cout<<N2++<<": "<<endl;
for(int i=0;i<p.size();i++)
{
cout<<p[i];
cout<<endl;
}
return out;
}
int main()
{
string name[n]={"ZhangSan","liSi","WangMaZi","XiaoMing","XiaoHua","XiaoZhang"};
string sex[n]={"boy","girl","boy","girl","boy","girl"};
int _rank[n]={1,2,3,4,5,6};
vector<string>Name;
vector<string>Sex;
vector<int>Rank;
Name.insert(Name.begin(),name,name+n);
Sex.insert(Sex.begin(),sex,sex+n);
Rank.insert(Rank.begin(),_rank,_rank+n);
vector<Information>Student;
for(int i=0;i<n;i++)
{
Information temp;
temp.studentName=Name[i];
temp.studentSex=Sex[i];
temp.studentRank=Rank[i];
Student.push_back(temp);
}
cout<<Student<<endl;
N1=1;
system("pause");
vector< vector<Information> >VEC;
for(int i=0;i<n;i++)
VEC.push_back(Student);
string name1[n]={"ZhangSan1","liSi2","WangMaZi3","XiaoMing4","XiaoHua5","XiaoZhang6"};
string sex1[n]={"boy1","girl2","boy3","girl4","boy5","girl6"};
int _rank1[n]={11,22,33,44,55,66};
vector<string>Name1;
vector<string>Sex1;
vector<int>Rank1;
Name1.insert(Name1.begin(),name1,name1+n);
Sex1.insert(Sex1.begin(),sex1,sex1+n);
Rank1.insert(Rank1.begin(),_rank1,_rank1+n);
vector<Information>Student1;
for(int i=0;i<n;i++)
{
Information temp;
temp.studentName=Name1[i];
temp.studentSex=Sex1[i];
temp.studentRank=Rank1[i];
Student1.push_back(temp);
}
cout<<VEC;
N1=1;
VEC.insert(VEC.begin()+2,2,Student1);
cout<<VEC;
N1=1;
VEC.erase(VEC.begin()+3);
cout<<VEC;
N1=1;
VEC.pop_back();
cout<<VEC;
//.......
return 0;
}
更多数据结构不再列举 本文参考了部分网络上的代码示例，加入了笔者自己的一些代码，如有不妥之处，肯请读者指正。
标签：
原文地址：http://www.cnblogs.com/yqbeyond/p/4455058.html
