实验四类的组合、继承、模板类、标准库

实验一

task1_1.cpp:

 1 #include<iostream>
 2 
 3 using std::cout;
 4 using std::endl;
 5 
 6 class A {
 7 public:
 8     A(int x0, int y0);
 9     void display()const;
10 
11 private:
12     int x, y;
13 };
14 
15 A::A(int x0, int y0) :x{ x0 }, y{ y0 } {
16 }
17 
18 void A::display()const {
19     cout << x << "," << y << endl;
20 }
21 
22 class B {
23 public:
24     B(double x0, double y0);
25     void display()const;
26 
27 private:
28     double x, y;
29 };
30 
31 B::B(double x0,double y0):x{x0},y{y0}{}
32 
33 void B::display()const {
34     cout << x << "," << y << endl;
35 }
36 
37 void test() {
38     cout << "测试类A:" << endl;
39     A a(3, 4);
40     a.display();
41 
42     cout << "\n测试类B:" << endl;
43     B b(3.2, 5.6);
44     b.display();
45 }
46 
47 int main() {
48     test();
49 }

运行结果：

task1_2.cpp:

 1 #include<iostream>
 2 #include<string>
 3 
 4 using std::cout;
 5 using std::endl;
 6 using std::string;
 7 
 8 template<typename T>
 9 class X {
10 public:
11     X(T x0, T y0);
12     void display();
13 
14 private:
15     T x, y;
16 };
17 
18 template<typename T>
19 X<T>::X(T x0, T y0) :x{ x0 }, y{ y0 } {
20 }
21 
22 template<typename T>
23 void X<T>::display() {
24     cout << x << "," << y << endl;
25 }
26 
27 void test() {
28     cout << "测试1：类模板X中的抽象类型T用int实例化" << endl;
29     X<int>x1(3, 4);
30     x1.display();
31 
32     cout << endl;
33 
34     cout << "测试2：类模板X中的抽象类型T用double实例化" << endl;
35     X<double>x2(3.2, 5.6);
36     x2.display();
37 
38     cout << endl;
39 
40     cout << "测试3：类模板X中的抽象类型T用string实例化" << endl;
41     X<string>x3("hello", "oop");
42     x3.display();
43 }
44 
45 int main() {
46     test();
47 }

运行结果：

实验二

代码

GradeCalc.hpp:

  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 }

task2.cpp:

 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 }

运行结果：

问题1：成绩存储在基类vector<int>的对象里。派生类方法是通过this指针指向vector<int>对象来访问成绩的。input是通过this指针指向基类vector<int>对象来存入数据的。

问题2：分母的功能是作为除数除以总分获得平均分。有影响，乘以1.0代表这个返回值是float类型，有小数点，能正常获得小数点后的值，如果没有就默认不保留小数点后的值，然后类型转换从int变为float型。

问题3：在compute成员函数里没用限制100以上的数据无效，虽然现实生活考试大部分100分满分，但有时人为输入成绩时会按错多按，导致无效成绩被录入。

实验三

代码：

GradeCalc.hpp:

  1 #pragma once
  2 #include <iostream>
  3 #include <vector>
  4 #include <string>
  5 #include <algorithm>
  6 #include <numeric>
  7 #include <iomanip>
  8 
  9 using std::vector;
 10 using std::string;
 11 using std::cin;
 12 using std::cout;
 13 using std::endl;
 14 
 15 class GradeCalc {
 16 public:
 17     GradeCalc(const string& cname, int size);
 18     void input();                             // 录入成绩
 19     void output() const;                      // 输出成绩
 20     void sort(bool ascending = false);        // 排序 (默认降序)
 21     int min() const;                          // 返回最低分
 22     int max() const;                          // 返回最高分
 23     float average() const;                    // 返回平均分
 24     void info();                              // 输出课程成绩信息 
 25 
 26 private:
 27     void compute();     // 成绩统计
 28 
 29 private:
 30     string course_name;     // 课程名
 31     int n;                  // 课程人数
 32     vector<int> grades;     // 课程成绩
 33     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]
 34     vector<double> rates = vector<double>(5, 0); // 保存各分数段比例 
 35 };
 36 
 37 GradeCalc::GradeCalc(const string& cname, int size) : course_name{ cname }, n{ size } {}
 38 
 39 void GradeCalc::input() {
 40     int grade;
 41 
 42     for (int i = 0; i < n; ++i) {
 43         cin >> grade;
 44         grades.push_back(grade);
 45     }
 46 }
 47 
 48 void GradeCalc::output() const {
 49     for (int grade : grades)
 50         cout << grade << " ";
 51     cout << endl;
 52 }
 53 
 54 void GradeCalc::sort(bool ascending) {
 55     if (ascending)
 56         std::sort(grades.begin(), grades.end());
 57     else
 58         std::sort(grades.begin(), grades.end(), std::greater<int>());
 59 
 60 }
 61 
 62 int GradeCalc::min() const {
 63     return *std::min_element(grades.begin(), grades.end());
 64 }
 65 
 66 int GradeCalc::max() const {
 67     return *std::max_element(grades.begin(), grades.end());
 68 }
 69 
 70 float GradeCalc::average() const {
 71     return std::accumulate(grades.begin(), grades.end(), 0) * 1.0 / n;
 72 }
 73 
 74 void GradeCalc::compute() {
 75     for (int grade : grades) {
 76         if (grade < 60)
 77             counts.at(0)++;
 78         else if (grade >= 60 && grade < 70)
 79             counts.at(1)++;
 80         else if (grade >= 70 && grade < 80)
 81             counts.at(2)++;
 82         else if (grade >= 80 && grade < 90)
 83             counts.at(3)++;
 84         else if (grade >= 90)
 85             counts.at(4)++;
 86     }
 87 
 88     for (int i = 0; i < rates.size(); ++i)
 89         rates.at(i) = counts.at(i) * 1.0 / n;
 90 }
 91 
 92 void GradeCalc::info() {
 93     cout << "课程名称:\t" << course_name << endl;
 94     cout << "排序后成绩: \t";
 95     sort();  output();
 96     cout << "最高分:\t" << max() << endl;
 97     cout << "最低分:\t" << min() << endl;
 98     cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl;
 99 
100     compute();  // 统计各分数段人数、比例
101 
102     vector<string> tmp{ "[0, 60)  ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]" };
103     for (int i = tmp.size() - 1; i >= 0; --i)
104         cout << tmp[i] << "\t: " << counts[i] << "人\t"
105         << std::fixed << std::setprecision(2) << rates[i] * 100 << "%" << endl;
106 }

task3.cpp:

 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 }

运行结果：

问题1：成绩存储在对象的元素vector<int>里。通过vector<int>对象的接口访问到的。实验二是指针指向的基类元素vector<int>里的值，实验三是对象的成员vector<int>里的值。

问题2：类可以通过继承可以获得基类的非私有成员函数并作为自己的接口，而类的组合是通过对象的元素，元素在通过其自带的接口来实现操作，两者方法不一样，使用时具体情况具体分析。

实验四

代码

task4_1.cpp:

 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;
10     cout << "s1:" << s1 << endl;
11     cout << "s2:" << s2 << endl;
12 }
13 
14 void test2() {
15     string s1, s2;
16     getline(cin, s1);
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, ' ');
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 }

运行结果：

问题1：

这段代码的作用是清除输入缓冲区中所有字符，直到遇到换行符 '\n' 为止。

task4_2.cpp:

 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 }

运行结果：

task4_3.cpp:

 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 }

运行结果：

问题2：

用途是清除输入缓冲区中所有字符，直到遇到换行符 '\n' 为止。

实验五

代码

grm.hpp:

 1 #pragma once
 2 #include<iostream>
 3 
 4 using namespace std;
 5 
 6 template<typename T>
 7 class GameResourceManager {
 8 private:
 9     T resource;
10 
11 public:
12     GameResourceManager(T res):resource{res}{}
13 
14     T get()const {
15         return resource;
16     }
17 
18     void update(T sum) {
19         resource += sum;
20         if (resource < 0)
21             resource = 0;
22     }
23 };

task5.cpp:

 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 int main() {
26     cout << "测试1：用float类型对类模板GameResourceManger实例化" << endl;
27     test1();
28     cout << endl;
29 
30     cout << "测试2：用int类型对类模板GameResourceManager实例化" << endl;
31     test2();
32 }

运行结果：

实验六

代码

Info.hpp:

 1 #pragma once
 2 #include<iostream>
 3 #include<string>
 4 
 5 using namespace std;
 6 
 7 class Info {
 8 private:
 9     string nickname;
10     string contact;
11     string city;
12     int number;
13 
14 public:
15     Info(string name,string con,string ci,int num):nickname{name},contact{con},city{ci},number{num}{}
16 
17     void display() {
18         cout << string(30, '-') << endl;
19         cout << "昵称：" << "\t" << nickname << endl;
20         cout << "联系方式：" << "\t" << contact << endl;
21         cout << "所在城市：" << "\t" << city << endl;
22         cout << "预定人数：" << "\t" << number << endl;
23     }
24 
25 };

task6.hpp:

 1 #include"info.hpp"
 2 #include<iostream>
 3 #include<string>
 4 #include<vector>
 5 
 6 using namespace std;
 7 
 8 int main() {
 9     vector<Info>audience_lst;
10     const int capaciry = 100;
11     string nickname, contact, city;
12     int last=100,number;
13     cout << "昵称         " << "联系方式（邮箱/手机号）     " << "所在城市      " << "预定参加人数" << endl;
14     while (cin >> nickname >> contact >> city >> number) {
15         if (nickname == "000")break;
16         int last1 = last;
17         last -=number ;
18         if (last < 0) {
19             cout << "对不起，只剩" << last1 << "个位置" << endl;
20             cout << "1.输入u，更新（update）预定信息" << endl;
21             cout << "2.输入q，退出预定" << endl;
22             cout << "你的选择：";
23             string n;
24             cin >> n;
25             if (n == "q")return 0;
26             if (n == "u") {
27                 cout << "请重新输入预定信息：" << endl;
28                 cin >> nickname >> contact >> city >> number;
29             }
30             audience_lst.push_back(Info(nickname, contact, city, number));
31         }
32         else {
33             audience_lst.push_back(Info(nickname, contact, city, number));
34         }
35     }
36     cout << "截至目前，一共有100位听众预约。预约听众信息如下：" << endl;
37     for (auto i : audience_lst) {
38         i.display();
39     }
40     cout << string(30, '-') << endl;
41 }

运行结果：

实验七

代码

date.h:

 1 #pragma once
 2 #ifndef  DATE H
 3 #define  DATE H
 4 class Date {
 5 private:
 6     int year;
 7     int month;
 8     int day;
 9     int totalDays;
10 public:
11     Date(int year, int month, int day);
12     int getYear()const { return year; }
13     int getMonth()const { return month; }
14     int getDay()const { return day; }
15     int getMaxDay()const;
16     bool isLeapYear()const {
17         return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
18     }
19     void show()const;
20     int distance(const Date& date)const {
21         return totalDays - date.totalDays;
22     }
23 };
24 #endif//  DATE H

date.cpp:

 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 int Date::getMaxDay()const {
20     if (isLeapYear() && month == 2)
21         return 29;
22     else return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
23 }
24 
25 void Date::show()const {
26     cout << getYear() << "-" << getMonth() << "-" << getDay();
27 }

accumulator.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

account.h:

 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

account.cpp:

 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 }

task7.cpp:

 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 }

运行结果：

总结：用了多个类，更精细化定义构造了各个函数，增加了功能。代码有些重复，过于繁琐。

posted @ 2024-11-18 18:53 霍学金阅读(15) 评论(0) 编辑收藏举报

刷新页面返回顶部

sqmylc

实验四类的组合、继承、模板类、标准库

公告

sqmylc

实验四 类的组合、继承、模板类、标准库

公告

实验四类的组合、继承、模板类、标准库