9.3.3

9.25
elem2是要删除的的最后一个元素之后的位置
所以当elem1=elem2时，什么也不会发生
当elem2是尾后迭代器，那么讲吧elem1到结尾全部删除
当elem1和elem2都是尾后迭代器，也什么都不会发生

9.26

#include <iostream>#include <vector>#include <list>using std::vector; using std::list; using std::cout; using std::endl; using std::end;int main(){    int ia[] = { 0, 1, 1, 2, 3, 5, 8, 13, 21, 55, 89 };    vector<int> vec(ia, end(ia));    list<int> lst(vec.begin(), vec.end());    for(auto it = lst.begin();  it != lst.end(); )        if(*it % 2) it = lst.erase(it);        else ++it;    for(auto it = vec.begin();  it != vec.end(); )        if(! (*it % 2 )) it = vec.erase(it);        else ++it;    cout << "list : ";    for(auto i : lst)   cout << i << " ";    cout << "\nvector : ";    for(auto i : vec)   cout << i << " ";    cout << std::endl;    return 0;}