类的组合、继承、模板类、标准库
实验任务一：
1 #include <iostream> 2 3 using std::cout; 4 using std::endl; 5 6 // 类A的定义 7 class A { 8 public: 9 A(int x0, int y0); 10 void display() const; 11 12 private: 13 int x, y; 14 }; 15 16 A::A(int x0, int y0): x{x0}, y{y0} { 17 } 18 19 void A::display() const { 20 cout << x << ", " << y << endl; 21 } 22 23 // 类B的定义 24 class B { 25 public: 26 B(double x0, double y0); 27 void display() const; 28 29 private: 30 double x, y; 31 }; 32 33 B::B(double x0, double y0): x{x0}, y{y0} { 34 } 35 36 void B::display() const { 37 cout << x << ", " << y << endl; 38 } 39 40 void test() { 41 cout << "测试类A: " << endl; 42 A a(3, 4); 43 a.display(); 44 45 cout << "\n测试类B: " << endl; 46 B b(3.2, 5.6); 47 b.display(); 48 } 49 50 int main() { 51 test(); 52 }
1 #include <iostream> 2 #include <string> 3 4 using std::cout; 5 using std::endl; 6 using std::string; 7 8 // 定义类模板 9 template<typename T> 10 class X{ 11 public: 12 X(T x0, T y0); 13 void display(); 14 15 private: 16 T x, y; 17 }; 18 19 template<typename T> 20 X<T>::X(T x0, T y0): x{x0}, y{y0} { 21 } 22 23 template<typename T> 24 void X<T>::display() { 25 cout << x << ", " << y << endl; 26 } 27 28 29 void test() { 30 cout << "测试1: 类模板X中的抽象类型T用int实例化" << endl; 31 X<int> x1(3, 4); 32 x1.display(); 33 34 cout << endl; 35 36 cout << "测试2: 类模板X中的抽象类型T用double实例化" << endl; 37 X<double> x2(3.2, 5.6); 38 x2.display(); 39 40 cout << endl; 41 42 cout << "测试3: 类模板X中的抽象类型T用string实例化" << endl; 43 X<string> x3("hello", "oop"); 44 x3.display(); 45 } 46 47 int main() { 48 test(); 49 }
实验任务二：
1 #include <iostream> 2 #include <vector> 3 #include <string> 4 #include <algorithm> 5 #include <numeric> 6 #include <iomanip> 7 8 using std::vector; 9 using std::string; 10 using std::cin; 11 using std::cout; 12 using std::endl; 13 14 class GradeCalc: public vector<int> { 15 public: 16 GradeCalc(const string &cname, int size); 17 void input(); // 录入成绩 18 void output() const; // 输出成绩 19 void sort(bool ascending = false); // 排序 (默认降序) 20 int min() const; // 返回最低分 21 int max() const; // 返回最高分 22 float average() const; // 返回平均分 23 void info(); // 输出课程成绩信息 24 25 private: 26 void compute(); // 成绩统计 27 28 private: 29 string course_name; // 课程名 30 int n; // 课程人数 31 vector<int> counts = vector<int>(5, 0); // 保存各分数段人数（[0, 60), [60, 70), [70, 80), [80, 90), [90, 100] 32 vector<double> rates = vector<double>(5, 0); // 保存各分数段比例 33 }; 34 35 GradeCalc::GradeCalc(const string &cname, int size): course_name{cname}, n{size} {} 36 37 void GradeCalc::input() { 38 int grade; 39 40 for(int i = 0; i < n; ++i) { 41 cin >> grade; 42 this->push_back(grade); 43 } 44 } 45 46 void GradeCalc::output() const { 47 for(auto ptr = this->begin(); ptr != this->end(); ++ptr) 48 cout << *ptr << " "; 49 cout << endl; 50 } 51 52 void GradeCalc::sort(bool ascending) { 53 if(ascending) 54 std::sort(this->begin(), this->end()); 55 else 56 std::sort(this->begin(), this->end(), std::greater<int>()); 57 } 58 59 int GradeCalc::min() const { 60 return *std::min_element(this->begin(), this->end()); 61 } 62 63 int GradeCalc::max() const { 64 return *std::max_element(this->begin(), this->end()); 65 } 66 67 float GradeCalc::average() const { 68 return std::accumulate(this->begin(), this->end(), 0) * 1.0 / n; 69 } 70 71 void GradeCalc::compute() { 72 for(int grade: *this) { 73 if(grade < 60) 74 counts.at(0)++; 75 else if(grade >= 60 && grade < 70) 76 counts.at(1)++; 77 else if(grade >= 70 && grade < 80) 78 counts.at(2)++; 79 else if(grade >= 80 && grade < 90) 80 counts.at(3)++; 81 else if(grade >= 90) 82 counts.at(4)++; 83 } 84 85 for(int i = 0; i < rates.size(); ++i) 86 rates.at(i) = counts.at(i) * 1.0 / n; 87 } 88 89 void GradeCalc::info() { 90 cout << "课程名称:\t" << course_name << endl; 91 cout << "排序后成绩: \t"; 92 sort(); output(); 93 cout << "最高分:\t" << max() << endl; 94 cout << "最低分:\t" << min() << endl; 95 cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl; 96 97 compute(); // 统计各分数段人数、比例 98 99 vector<string> tmp{"[0, 60) ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]"}; 100 for(int i = tmp.size()-1; i >= 0; --i) 101 cout << tmp[i] << "\t: " << counts[i] << "人\t" 102 << std::fixed << std::setprecision(2) << rates[i]*100 << "%" << endl; 103 }
1 #include "GradeCalc.hpp" 2 #include <iomanip> 3 4 void test() { 5 int n; 6 cout << "输入班级人数: "; 7 cin >> n; 8 9 GradeCalc c1("OOP", n); 10 11 cout << "录入成绩: " << endl;; 12 c1.input(); 13 cout << "输出成绩: " << endl; 14 c1.output(); 15 16 cout << string(20, '*') + "课程成绩信息" + string(20, '*') << endl; 17 c1.info(); 18 } 19 20 int main() { 21 test(); 22 }
问题一：
成绩存储在vector<int>类数组中；sort,min,max,average,output是通过vector<int>中的begin(),end()接口访问每个成绩的；input是通过vector<int>中的push_back()接口实现数据存入对象的
问题二：
功能：分母为人数，用来计算总分数的平均值；去掉*1.0代码，结果影响了平均分精度；*1.0是为提高精度的
问题三：
可以考虑使用动态数组，便于更新已有成绩或增减成员。
可以增加成绩中位数、标准差等指标。
增加参数设置，使得输出信息可以自定义，例如输出成绩分布、分数段详情等
实验任务三：
1 #include <iostream> 2 #include <vector> 3 #include <string> 4 #include <algorithm> 5 #include <numeric> 6 #include <iomanip> 7 8 using std::vector; 9 using std::string; 10 using std::cin; 11 using std::cout; 12 using std::endl; 13 14 class GradeCalc { 15 public: 16 GradeCalc(const string &cname, int size); 17 void input(); // 录入成绩 18 void output() const; // 输出成绩 19 void sort(bool ascending = false); // 排序 (默认降序) 20 int min() const; // 返回最低分 21 int max() const; // 返回最高分 22 float average() const; // 返回平均分 23 void info(); // 输出课程成绩信息 24 25 private: 26 void compute(); // 成绩统计 27 28 private: 29 string course_name; // 课程名 30 int n; // 课程人数 31 vector<int> grades; // 课程成绩 32 vector<int> counts = vector<int>(5, 0); // 保存各分数段人数（[0, 60), [60, 70), [70, 80), [80, 90), [90, 100] 33 vector<double> rates = vector<double>(5, 0); // 保存各分数段比例 34 }; 35 36 GradeCalc::GradeCalc(const string &cname, int size): course_name{cname}, n{size} {} 37 38 void GradeCalc::input() { 39 int grade; 40 41 for(int i = 0; i < n; ++i) { 42 cin >> grade; 43 grades.push_back(grade); 44 } 45 } 46 47 void GradeCalc::output() const { 48 for(int grade: grades) 49 cout << grade << " "; 50 cout << endl; 51 } 52 53 void GradeCalc::sort(bool ascending) { 54 if(ascending) 55 std::sort(grades.begin(), grades.end()); 56 else 57 std::sort(grades.begin(), grades.end(), std::greater<int>()); 58 59 } 60 61 int GradeCalc::min() const { 62 return *std::min_element(grades.begin(), grades.end()); 63 } 64 65 int GradeCalc::max() const { 66 return *std::max_element(grades.begin(), grades.end()); 67 } 68 69 float GradeCalc::average() const { 70 return std::accumulate(grades.begin(), grades.end(), 0) * 1.0 / n; 71 } 72 73 void GradeCalc::compute() { 74 for(int grade: grades) { 75 if(grade < 60) 76 counts.at(0)++; 77 else if(grade >= 60 && grade < 70) 78 counts.at(1)++; 79 else if(grade >= 70 && grade < 80) 80 counts.at(2)++; 81 else if(grade >= 80 && grade < 90) 82 counts.at(3)++; 83 else if(grade >= 90) 84 counts.at(4)++; 85 } 86 87 for(int i = 0; i < rates.size(); ++i) 88 rates.at(i) = counts.at(i) *1.0 / n; 89 } 90 91 void GradeCalc::info() { 92 cout << "课程名称:\t" << course_name << endl; 93 cout << "排序后成绩: \t"; 94 sort(); output(); 95 cout << "最高分:\t" << max() << endl; 96 cout << "最低分:\t" << min() << endl; 97 cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl; 98 99 compute(); // 统计各分数段人数、比例 100 101 vector<string> tmp{"[0, 60) ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]"}; 102 for(int i = tmp.size()-1; i >= 0; --i) 103 cout << tmp[i] << "\t: " << counts[i] << "人\t" 104 << std::fixed << std::setprecision(2) << rates[i]*100 << "%" << endl; 105 }
1 #include "GradeCalc.hpp" 2 #include <iomanip> 3 4 void test() { 5 int n; 6 cout << "输入班级人数: "; 7 cin >> n; 8 9 GradeCalc c1("OOP", n); 10 11 cout << "录入成绩: " << endl;; 12 c1.input(); 13 cout << "输出成绩: " << endl; 14 c1.output(); 15 16 cout << string(20, '*') + "课程成绩信息" + string(20, '*') << endl; 17 c1.info(); 18 } 19 20 int main() { 21 test(); 22 }
问题1：成绩被保存在类的私有成员grades中，其类型为vector<int>。对于排序、求最值、计算平均值和输出等操作，都是通过grades.begin()和grades.end()接口来访问成绩的。与之前的代码相比，这次实验新增了vector<int>类型的counts和vector<double>类型的rates对象，而在类的成员方法中，直接通过grades.来调用继承的相关方法。
问题2：面向对象编程允许在不改变主要代码逻辑和接口的情况下对类的设计接口及内部细节进行修改。这样可以使代码的修改和优化更加方便和可控。
实验任务四：
1 #include <iostream> 2 #include <string> 3 #include <limits> 4 5 using namespace std; 6 7 void test1() { 8 string s1, s2; 9 cin >> s1 >> s2; // cin: 从输入流读取字符串, 碰到空白符(空格/回车/Tab)即结束 10 cout << "s1: " << s1 << endl; 11 cout << "s2: " << s2 << endl; 12 } 13 14 void test2() { 15 string s1, s2; 16 getline(cin, s1); // getline(): 从输入流中提取字符串，直到遇到换行符 17 getline(cin, s2); 18 cout << "s1: " << s1 << endl; 19 cout << "s2: " << s2 << endl; 20 } 21 22 void test3() { 23 string s1, s2; 24 getline(cin, s1, ' '); //从输入流中提取字符串，直到遇到指定分隔符 25 getline(cin, s2); 26 cout << "s1: " << s1 << endl; 27 cout << "s2: " << s2 << endl; 28 } 29 30 int main() { 31 cout << "测试1: 使用标准输入流对象cin输入字符串" << endl; 32 test1(); 33 cout << endl; 34 35 cin.ignore(numeric_limits<streamsize>::max(), '\n'); 36 37 cout << "测试2: 使用函数getline()输入字符串" << endl; 38 test2(); 39 cout << endl; 40 41 cout << "测试3: 使用函数getline()输入字符串, 指定字符串分隔符" << endl; 42 test3(); 43 }
问题一：去掉后：
用途：清空输入缓存区,防止错误输入
1 #include <iostream> 2 #include <string> 3 #include <vector> 4 #include <limits> 5 6 using namespace std; 7 8 void output(const vector<string> &v) { 9 for(auto &s: v) 10 cout << s << endl; 11 } 12 13 void test() { 14 int n; 15 while(cout << "Enter n: ", cin >> n) { 16 vector<string> v1; 17 18 for(int i = 0; i < n; ++i) { 19 string s; 20 cin >> s; 21 v1.push_back(s); 22 } 23 24 cout << "output v1: " << endl; 25 output(v1); 26 cout << endl; 27 } 28 } 29 30 int main() { 31 cout << "测试: 使用cin多组输入字符串" << endl; 32 test(); 33 }
1 #include <iostream> 2 #include <string> 3 #include <vector> 4 #include <limits> 5 6 using namespace std; 7 8 void output(const vector<string> &v) { 9 for(auto &s: v) 10 cout << s << endl; 11 } 12 13 void test() { 14 int n; 15 while(cout << "Enter n: ", cin >> n) { 16 cin.ignore(numeric_limits<streamsize>::max(), '\n'); 17 18 vector<string> v2; 19 20 for(int i = 0; i < n; ++i) { 21 string s; 22 getline(cin, s); 23 v2.push_back(s); 24 } 25 cout << "output v2: " << endl; 26 output(v2); 27 cout << endl; 28 } 29 } 30 31 int main() { 32 cout << "测试: 使用函数getline()多组输入字符串" << endl; 33 test(); 34 }
问题二：修改后结果
用途：清除输入流中未被 cin >> n 读取的换行符，以确保接下来的 getline 函数可以正确读取用户输入的字符串，避免由于残留的换行符导致它立即返回空字符串。
实验任务五：
1 #include<iostream> 2 3 4 using std::cout; 5 using std::endl; 6 7 template<typename T> 8 class GameResourceManager{ 9 public: 10 GameResourceManager(T x0); 11 T get(); 12 void update(T y0); 13 private: 14 T x; 15 }; 16 17 template<typename T> 18 GameResourceManager<T>::GameResourceManager(T x0):x{x0} { 19 } 20 21 template<typename T> 22 T GameResourceManager<T>::get() { 23 return x; 24 } 25 26 template<typename T> 27 void GameResourceManager<T>::update(T y0) { 28 x+=y0; 29 if(x<0) 30 x=0; 31 }
1 #include "grm.hpp" 2 #include <iostream> 3 4 using std::cout; 5 using std::endl; 6 7 void test1() { 8 GameResourceManager<float> HP_manager(99.99); 9 cout << "当前生命值: " << HP_manager.get() << endl; 10 HP_manager.update(9.99); 11 cout << "增加9.99生命值后, 当前生命值: " << HP_manager.get() << endl; 12 HP_manager.update(-999.99); 13 cout <<"减少999.99生命值后, 当前生命值: " << HP_manager.get() << endl; 14 } 15 16 void test2() { 17 GameResourceManager<int> Gold_manager(100); 18 cout << "当前金币数量: " << Gold_manager.get() << endl; 19 Gold_manager.update(50); 20 cout << "增加50个金币后, 当前金币数量: " << Gold_manager.get() << endl; 21 Gold_manager.update(-99); 22 cout <<"减少99个金币后, 当前金币数量: " << Gold_manager.get() << endl; 23 } 24 25 26 int main() { 27 cout << "测试1: 用float类型对类模板GameResourceManager实例化" << endl; 28 test1(); 29 cout << endl; 30 31 cout << "测试2: 用int类型对类模板GameResourceManager实例化" << endl; 32 test2(); 33 }
实验任务六
1 #include<iostream> 2 #include<string> 3 #include <iomanip> 4 5 using std::cout; 6 using std::endl; 7 using std::string; 8 using std::setw; 9 10 class Info{ 11 public: 12 Info(string nickname0,string contact0,string city0,int n0); 13 void display(); 14 private: 15 string nickname; 16 string contact; 17 string city; 18 int n; 19 }; 20 21 Info::Info(string nickname0,string contact0,string city0,int n0):nickname(nickname0),contact(contact0),city(city0),n(n0) { 22 } 23 24 void Info::display() 25 { 26 27 cout<<"-------------------------------\n"; 28 cout<<setw(10)<<"昵称"<<nickname<<endl; 29 cout<<setw(10)<<"联系方式"<<contact<<endl; 30 cout<<setw(10)<<"所在城市"<<city<<endl; 31 cout<<setw(10)<<"预定人数"<<n<<endl; 32 }
1 #include<iostream> 2 #include<string> 3 #include<vector> 4 #include <iomanip> 5 #include"info.hpp" 6 7 using namespace std; 8 using std::setw; 9 10 int main() 11 { 12 const int capacity=100; 13 vector<Info> audience_lst; 14 char choice; 15 string nickname,contact,city; 16 int n; 17 cout<<"录入用户预约信息：\n"<<endl; 18 cout<<"昵称"<<setw(30)<<"联系方式（邮箱/手机号）"<<setw(20)<<"所在城市"<<setw(20)<<"预定参加人数"<<endl; 19 int i=0,sum=0; 20 while((cin>>nickname>>contact>>city>>n)) 21 { 22 //cin>>nickname>>contact>>city>>n; 23 audience_lst.push_back(Info(nickname,contact,city,n)); 24 sum+=n; 25 i++; 26 if(sum>capacity) 27 { 28 sum-=n; 29 cout<<"对不起，只剩"<<capacity-sum<<"个位置。\n"; 30 cout<<"1.输入u,更新（update）预定信息\n"; 31 cout<<"2.输入q,退出预定\n"; 32 cout<<"你的选择："; 33 cin>>choice; 34 if(choice=='u') 35 { 36 cout<<"请重新输入预定信息：\n"; 37 i--; 38 continue; 39 } 40 else 41 { 42 break; 43 } 44 } 45 46 } 47 48 cout<<"截至目前，一共有"<<sum<<"位听众预约。预约听众信息如下：\n"; 49 for(int j=0;j<i;j++) 50 { 51 audience_lst[j].display(); 52 } 53 }
实验任务7：
1 #include"account.h" 2 #include<iostream> 3 4 using namespace std; 5 6 int main() { 7 Date date(2008, 11, 1); 8 SavingsAccount sa1(date, "S3755217", 0.015); 9 SavingsAccount sa2(date, "02342342", 0.015); 10 CreditAccount ca(date, "C5392394", 10000, 0.0005, 50); 11 12 sa1.deposit(Date(2008, 11, 5), 5000, "salary"); 13 ca.withdraw(Date(2008, 11, 15), 2000, "buy a cell"); 14 sa2.deposit(Date(2008, 11, 25), 10000, "sell stock 0323"); 15 16 ca.settle(Date(2008, 12, 1)); 17 18 ca.deposit(Date(2008, 12, 1), 2016, "repay the credit"); 19 sa1.deposit(Date(2008, 12, 5), 5500, "salary"); 20 21 sa1.settle(Date(2009, 1, 1)); 22 sa2.settle(Date(2009, 1, 1)); 23 ca.settle(Date(2009, 1, 1)); 24 25 cout << endl; 26 sa1.show(); cout << endl; 27 sa2.show(); cout << endl; 28 ca.show(); cout << endl; 29 cout << "Total:" << Account::getTotal() << endl; 30 return 0; 31 }
1 #include"account.h" 2 #include<cmath> 3 #include<iostream> 4 using namespace std; 5 double Account::total = 0; 6 7 Account::Account(const Date& date, const string& id) :id{ id }, balance{ 0 } { 8 date.show(); cout << "\t#" << id << "created" << endl; 9 } 10 11 12 void Account::record(const Date& date, double amount, const string& desc) { 13 amount = floor(amount * 100 + 0.5) / 100; 14 balance += amount; 15 total += amount; 16 date.show(); 17 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl; 18 } 19 20 void Account::show()const { cout << id << "\tBalance:" << balance; } 21 void Account::error(const string& msg)const { 22 cout << "Error(#" << id << "):" << msg << endl; 23 } 24 25 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :Account(date, id), rate(rate), acc(date, 0) {} 26 27 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) { 28 record(date, amount, desc); 29 acc.change(date, getBalance()); 30 } 31 32 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) { 33 if (amount > getBalance()) { 34 error("not enough money"); 35 } 36 else { 37 record(date, -amount, desc); 38 acc.change(date, getBalance()); 39 } 40 } 41 42 void SavingsAccount::settle(const Date& date) { 43 double interest = acc.getSum(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1)); 44 if (interest != 0)record(date, interest, "interest"); 45 acc.reset(date, getBalance()); 46 } 47 48 CreditAccount::CreditAccount(const Date& date, const string& id, double credit, double rate, double fee) :Account(date, id), credit(credit), rate(rate), fee(fee), acc(date, 0) {} 49 50 void CreditAccount::deposit(const Date& date, double amount, const string& desc) { 51 record(date, amount, desc); 52 acc.change(date, getDebt()); 53 } 54 55 void CreditAccount::withdraw(const Date& date, double amount, const string& desc) { 56 if (amount - getBalance() > credit) { 57 error("not enough credit"); 58 } 59 else { 60 record(date, -amount, desc); 61 acc.change(date, getDebt()); 62 } 63 } 64 65 void CreditAccount::settle(const Date& date) { 66 double interest = acc.getSum(date) * rate; 67 if (interest != 0)record(date, interest, "interest"); 68 if (date.getMonth() == 1) 69 record(date, -fee, "annual fee"); 70 acc.reset(date, getDebt()); 71 } 72 73 void CreditAccount::show()const { 74 Account::show(); 75 cout << "\tAvailable credit:" << getAvailableCredit(); 76 }
1 #pragma once 2 #ifndef ACCOUNT H 3 #define ACCOUNT H 4 #include"date.h" 5 #include"accumulator.h" 6 #include<string> 7 class Account { 8 private: 9 std::string id; 10 double balance; 11 static double total; 12 protected: 13 Account(const Date& date, const std::string& id); 14 void record(const Date& date, double amount, const std::string& desc); 15 void error(const std::string& msg)const; 16 public: 17 const std::string& getId()const { return id; } 18 double getBalance()const { return balance; } 19 static double getTotal() { return total; } 20 21 void show()const; 22 }; 23 class SavingsAccount :public Account { 24 private: 25 Accumulator acc; 26 double rate; 27 public: 28 SavingsAccount(const Date& date, const std::string& id, double rate); 29 double getRate()const { return rate; } 30 31 void deposit(const Date& date, double amount, const std::string& desc); 32 void withdraw(const Date& date, double amount, const std::string& desc); 33 void settle(const Date& date); 34 }; 35 class CreditAccount :public Account { 36 private: 37 Accumulator acc; 38 double credit; 39 double rate; 40 double fee; 41 double getDebt()const { 42 double balance = getBalance(); 43 return (balance < 0 ? balance : 0); 44 } 45 public: 46 CreditAccount(const Date& date, const std::string& id, double credit, double rate, double fee); 47 double getCredit()const { return credit; } 48 double getRate()const { return rate; } 49 double getAvailableCredit()const { 50 if (getBalance() < 0) 51 return credit + getBalance(); 52 else 53 return credit; 54 } 55 void deposit(const Date& date, double amount, const std::string& desc); 56 void withdraw(const Date& date, double amount, const std::string& desc); 57 void settle(const Date& date); 58 void show()const; 59 }; 60 #endif//ACCOUNT H
1 #pragma once 2 #ifndef ACCUMULATOR H 3 #define ACCUMULATOR H 4 #include"date.h" 5 class Accumulator { 6 private: 7 Date lastDate; 8 double value; 9 double sum; 10 public: 11 Accumulator(const Date& date, double value) :lastDate(date), value(value), sum{ 0 } { 12 } 13 14 double getSum(const Date& date)const { 15 return sum + value * date.distance(lastDate); 16 } 17 18 void change(const Date& date, double value) { 19 sum = getSum(date); 20 lastDate = date; this->value = value; 21 } 22 23 void reset(const Date& date, double value) { 24 lastDate = date; this->value = value; sum = 0; 25 } 26 }; 27 #endif//ACCUMULATOR H
1 #include "date.h" 2 #include <iostream> 3 #include <cstdlib> 4 using namespace std; 5 namespace { 6 const int DAYS_BEFORE_MONTH[]={0,31,59,90,120,151,181,212,243,273,304,334,365}; 7 } 8 Date::Date(int year,int month,int day):year(year),month(month),day(day) { 9 if(day<=0||day>getMaxDay()) { 10 cout<<"Invalid date:"; 11 show(); 12 cout<<endl; 13 exit(1); 14 } 15 int years=year-1; 16 totalDays = years *365+years/4-years/100+years/400+DAYS_BEFORE_MONTH[month-1]+day; 17 if(isLeapYear()&&month>2) totalDays++; 18 } 19 20 int Date::getMaxDay() const { 21 if(isLeapYear()&&month==2) 22 return 29; 23 else 24 return DAYS_BEFORE_MONTH[month]-DAYS_BEFORE_MONTH[month-1]; 25 } 26 27 void Date::show() const { 28 cout<<getYear()<<"-"<<getMonth()<<"-"<<getDay(); 29 }
1 #ifndef __DATE_H__ 2 #define __DATE_H__ 3 class Date{ 4 private: 5 int year; 6 int month; 7 int day; 8 int totalDays; 9 public: 10 Date(int year,int month,int day); 11 int getYear() const {return year;} 12 int getMonth() const {return month;} 13 int getDay() const {return day;} 14 int getMaxDay() const; 15 bool isLeapYear() const { 16 return year%4==0 && year%100 !=0 ||year%400==0; 17 } 18 void show() const; 19 20 int distance(const Date& date) const { 21 return totalDays-date.totalDays; 22 } 23 }; 24 #endif //__DATE_H__
运用了类的派生的思想，使得派生类处理每一笔具体账目时可以调用record函数来改变余额并输出账目信息，提高了代码复用性。
通过采用继承方式，降低了代码的重复性，从而实现功能的扩展，使得程序在后续的修改和维护中更加方便。
实验总结：
在本次实验中，我深入学习了C++中的类模板和派生类的定义与使用，掌握了如何通过类的组合机制（has-a）和继承机制（is-a）来设计灵活的类结构。通过实践标准库中的string和vector，我能够根据具体问题场景灵活运用这些工具。此外，我运用面向对象的思维进行设计，结合标准库和自定义类，成功解决了实际问题。这次实验不仅加深了我对C++面向对象编程的理解，也提升了我的编程能力和问题解决能力。
