一道面试题

#include <iostream>using namespace std;class Base{public:Base() { cout << "100" << endl; }virtual ~Base() { cout << "110" << endl; }};class Derived_A : public Base{public:Derived_A() { cout << "200" << endl; }~Derived_A() { cout << "210" << endl; }};class Derived_B : public Derived_A{public:Derived_B() { cout << "300" << endl; }~Derived_B() { cout << "310" << endl; }};int main(){Base * base = new Derived_B;Derived_A * pa = dynamic_cast<Derived_A*>(base);delete pa;return 0;}

三道笔试：

1. 写一个函数，输出101到200之间的数，并计数。

2. 写一个生成密码的函数，参数为密码长度，要求同时包含大小写和数字。

3. 写一个函数判断IP地址是否合法。