迭代器iterator

//读入一组整数到vector对象，计算并输出每对相邻元素的和
//使用迭代器访问vector中的元素
#include <iostream>
#include <vector>
using namespace std;


int main(void)
{
cout<<"Enter numbers :"<<endl;

vector<int> ivec;
int ival;
while(cin>>ival)
{
ivec.push_back(ival);
}


//计算相邻元素的和，并输出
if(ivec.size()==0)
cout<<"No elements ?"<<endl;


cout<<"Sum of each pair of adjacent elements in the vector : "<<endl;


vector<int>::size_type cnt=0;
for(vector<int>::iterator iter=ivec.begin();iter < ivec.end()-1 ; iter = iter + 2)
{
cout<<*iter + *(iter+1)<<"\t";
}


if(ivec.size() % 2 == 1)
cout<<endl<<"The last element is not sumed and its value is "
<<*(ivec.end()-1)<<endl;


system("pause");
return 0;
}