C++编程填空：构造与析构

Question

描述

请完善程序，使得所有类型能够正确初始和消亡

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
// 在此处补充你的代码
int main(){
    int n;
    cin >> n;
    for (int i = 1; i<=n; i++) {
        int x;
        cin >> x;
        if (x == 0) {
            A *a = new A();
            delete a;
        }else {
            A *a = new B();
            delete a;
        }
    }
    return 0;   
}

样例输入

3
1 0 1

样例输出

New A
New B
Delete B
Delete A
New A 
Delete A
New A
New B
Delete B
Delete A

http://cxsjsx.openjudge.cn/2018midexamcloze/8/

Answer 1

class A
{
public:
   A(){cout<<"New A"<<endl;}
   virtual ~A(){cout<<"Delete A"<<endl;}
};
class B:public A
{
public:
    B(){cout<<"New B"<<endl;}
    virtual ~B(){cout<<"Delete B"<<endl;}
};