C++ primer 5th课后题 9.19、9.20、9.26、9.27、9.28

//习题9.19int main(){    string str;    deque<string> dq;    while (cin >> str) {        dq.push_back(str);    }    //iterator     for (auto sb = dq.cbegin(); sb != dq.cend(); sb++)         cout << *sb << endl;}//习题9.20int main(){    list<int> lit{0,1,2,3,4,5,6,7,8,9};    deque<int> dq1, dq2;    for (auto i : lit) {        if (i % 2)            dq2.push_back(i);        else            dq1.push_back(i);    }    for (auto j : dq1)        cout << j << endl;     for (auto j : dq2)        cout << j << endl;}//习题9.26int main(){       int ia[] = { 0, 1, 1, 2, 3, 5, 8, 13, 21 , 55, 89 };    vector<int> v1;    list<int> lt1;    v1.assign(ia, ia + 11);    lt1.assign(ia, ia + 11);    auto vb = v1.begin();    auto lb = lt1.begin();    //vector<int>::iterator vb = v1.begin();    while(vb != v1.end()) {        if (!((*vb) % 2))            vb = v1.erase(vb);//擦出后将返回值给vb，否则vb自己不会增加            v1.erase(vb);        else            vb++;    }    cout << "奇数为：" << endl;    for (auto i : v1)        cout << i << endl;    while (lb != lt1.end()) {        if ((*lb) % 2)            lb = lt1.erase(lb);        else            lb++;    }    cout << "偶数为：" << endl;    for (auto i : lt1)        cout << i << endl;    return 0;}//习题9.27int main(){    forward_list<int> flt{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};    auto fltbeg = flt.begin();    auto flt_before = flt.before_begin();    //for (auto i : flt)    cout << "原内容为：" << endl;    for (auto i : flt) {        cout << i << " ";    }    cout << endl;    while(fltbeg != flt.end()) {        if (*fltbeg % 2)            fltbeg = flt.erase_after(flt_before);//将flt_before后的元素删除，相当于将其后所有元素往前提，fltbeg指向新提过来的元素        else        {            flt_before++;            fltbeg++;//        }    }    cout << "去除奇数后：" << endl;    for (auto i : flt) {        cout << i << " ";    }}//习题9.28void test_insert(forward_list<string> &fl1, string str1, string str2){    bool flag = false;    auto flbeg = fl1.begin();    auto flbef = fl1.before_begin();    while (flbeg != fl1.end()) {        if (*flbeg == str1) {            flbeg = fl1.insert_after(flbeg, str2);//注意insert与erase的区别            flag = true;        }        flbef = flbeg;//forward_list 不支持--操作，故为了取得end前元素的迭代器不可以end--,只能这样        flbeg++;    }    if (!flag)        fl1.insert_after(flbef, str2);}int main(){    forward_list<string> fl1{"I", "have", "a", "dream"};    cout << "1" << endl;    test_insert(fl1, "d", "!");     for (auto i : fl1) {        cout << i << " ";    }    cout << endl;}