#include <iostream>
#include <vector>
using namespace std;
int main()
{
	std::vector<int> ve1;

	ve1.push_back(1);
	ve1.push_back(2);
	ve1.push_back(3);
	ve1.push_back(4);
	ve1.push_back(5);
	ve1.push_back(6);

	std::vector<int>::iterator it;
	cout<<"删除前的元素：";
	for (it=ve1.begin();it!=ve1.end();++it)
	{
		cout<<" "<<*it;

	}
	cout<<endl;


	// 这里移除的算法复杂度是O(1)，将待删除元素与最后一个元素交换再pop_back
	int idx=0;
	if (static_cast<size_t>(idx) == ve1.size()-1)
	{
		ve1.pop_back();
	}
	else
	{
	   iter_swap(ve1.begin()+idx, ve1.end()-1);
	   ve1.pop_back();
	}

	cout<<"删除后的元素：";
	for (it=ve1.begin();it!=ve1.end();++it)
	{
		cout<<" "<<*it;

	}
	 cout<<endl;
	 system("pause");
	return 0;
}