问题描述:
改进课堂上的“用户信息操作撤销”实例,使得系统可以实现多次撤销(可以使用HashMap、ArrayList等集合数据结构实现)。
C++代码:
#include<iostream> #include<string> #include<vector> using namespace std; //备忘录 class Memento { private: string account; string password; string telNo; public: Memento(string account, string password, string telNo) { this->account = account; this->password = password; this->telNo = telNo; } string getAccount() { return account; } void setAccount(string account) { this->account = account; } string getPassword() { return password; } void setPassword(string password) { this->password = password; } string getTelNo() { return telNo; } void setTelNo(string telNo) { this->telNo = telNo; } }; //发起者 class UserInfoDTO { private: string account; string password; string telNo; public: string getAccount() { return account; } void setAccount(string account) { this->account = account; } string getPassword() { return password; } void setPassword(string password) { this->password = password; } string getTelNo() { return telNo; } void setTelNo(string telNo) { this->telNo = telNo; } Memento saveMemento() { Memento memento(account, password, telNo); return memento; } void restoreMenmento(Memento memento) { this->account = memento.getAccount(); this->password = memento.getPassword(); this->telNo = memento.getTelNo(); } void show() { cout << "帐号:" + this->account << endl; cout << "密码:" + this->password << endl; cout << "电话:" + this->telNo << endl; } }; //管理者 class Caretaker { private: vector<Memento>mementos; public: Memento getMemento(int i) { return mementos.at(i); } void setMemento(Memento memento) { mementos.push_back(memento); } }; //测试函数 int main() { int index = -1; UserInfoDTO user; Caretaker taker; user.setAccount("张三"); user.setPassword("123456"); user.setTelNo("18800000000"); cout << "状态一:" << endl; taker.setMemento(user.saveMemento()); index++; user.show(); cout << "----------------------------------" << endl; user.setPassword("111111"); user.setTelNo("18800001111"); cout << "状态二:" << endl; taker.setMemento(user.saveMemento()); index++; user.show(); cout << "----------------------------------" << endl; user.setPassword("222222"); user.setTelNo("18800002222"); cout << "状态三:" << endl; user.show(); cout << "----------------------------------" << endl; cout << "回到状态二:" << endl; index--; user.restoreMenmento(taker.getMemento(1)); user.show(); cout << "----------------------------------" << endl; cout << "回到状态一:" << endl; index --; user.restoreMenmento(taker.getMemento(0)); user.show(); cout << "----------------------------------" << endl; }
运行结果: