vector删除单个元素

vector<T>::iterator本来就是随即存取的啊，可以直接在其对象上加或者减去一定的偏移量：
#include <iostream>
#include <string>
#include <vector>

using namespace std;

int
main()
{
    vector<int> ivec;
    for(int i = 0; i < 10; ++i)
        ivec.push_back(i*2);
    for(vector<int>::iterator it = ivec.begin(); it != ivec.end(); ++it)
        cout<<*it<<endl;
    ivec.erase(ivec.begin()+3);
    for(vector<int>::iterator it = ivec.begin(); it != ivec.end(); ++it)
        cout<<*it<<endl;
    return 0;
}