实验四类的组合、继承、模板类、标准库

实验任务一

task1_1.cpp

 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 }

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task1_2.cpp

 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 }

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实验任务二

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 }

View Code

demo2.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 }

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问题一：成绩储存在vector<int>中，通过基类的访问函数来访问基类的数据对象获取每个成绩，input方法通过push_back()来将数据存入对象；

问题二：accumulate累加的和是整数，乘1.0使结果变成double类型；去掉后重新编译结果有影响；

问题三：对于成绩应该还有高于平均分和低于平均分的划分，让成绩分布更加直观

实验任务三

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 {
 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 }

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demo3.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 }

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问题一：成绩储存在grades这个vector<int>中，都是通过vector<int>grades接口访问。实验二是通过对vector的继承后再进行编写程序，用到了很多基类的接口，也用到了很多this指针。

问题二：面向对象编程时只要确定了接口后，编写程序可以由多人共同完成，最后进行整合就可以了。

实验任务四

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;  // 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 }

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问题1：

line35中这个函数的作用是从输入流中提取和丢弃字符，这行代码的功能是从标准输入流cin中忽略尽可能多的字符，直到遇到换行符'\n'为止，这个操作用于清除输入缓冲区中剩余的不需要的字符。

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 }

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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 }

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问题二：

line16中这个函数的作用是从输入流中提取和丢弃字符，这行代码的功能是从标准输入流cin中忽略尽可能多的字符，直到遇到换行符'\n'为止，这个操作用于清除输入缓冲区中剩余的不需要的字符。

实验任务五

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

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grm.hpp

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

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实验任务六

Info.hpp

 1 #include <iostream>
 2 #include <string>
 3 
 4 class Info {
 5 public:
 6     Info(std::string nick, std::string cont, std::string c, int num)
 7         :nickname(nick), contact(cont), city(c), n(num) {}
 8     void display() const {
 9         std::cout << "昵称: " << nickname << std::endl;
10         std::cout << "联系方式: " << contact << std::endl;
11         std::cout << "所在城市: " << city << std::endl;
12         std::cout << "预定人数: " << n << std::endl;
13     }
14 private:
15     std::string nickname;
16     std::string contact;
17     std::string city;
18     int n;
19 };

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Info.cpp

 1 #include <iostream>
 2 #include <vector>
 3 #include "info.hpp"
 4 #include <limits>
 5 using std::cout;
 6 using std::cin;
 7 using std::endl;
 8 using std::string;
 9 const int capacity = 100;
10 
11 int main() {
12     std::vector<Info> audience_list;
13     int total_count = 0;
14 
15     while (true) {
16         if (total_count >= capacity) {
17             cout << "对不起，只剩" << (capacity - total_count) << "个位置。" << endl;
18             break;
19         }
20 
21         string choice;
22         cout << "1. 输入u，录入\更新预定信息" <<endl;
23         cout << "2. 输入q，退出预定" << endl;
24         cout << "你的选择: ";
25         cin >> choice;
26 
27         if (choice == "q") {
28             break;
29         } else if (choice == "u") {
30             string nick, cont, city;
31             int num;
32             cout << "请输入预定信息:" <<endl;
33             cout << "昵称: ";
34             cin >> nick;
35             cout << "联系方式(邮箱/手机号): ";
36             cin >> cont;
37             cout << "所在城市: ";
38             cin >> city;
39             cout << "预定人数: ";
40             cin >> num;
41             
42             if (total_count + num <= capacity) {
43                 audience_list.push_back(Info(nick, cont, city, num));
44                 total_count += num;
45             } else {
46                cout << "对不起，只剩" <<capacity - total_count << "个位置" <<endl;
47             }
48     }
49     }
50 
51     cout << "截至目前，一共有" << total_count << "位听众预约。预约听众如下:" <<endl;
52     for (const Info& info : audience_list) {
53         cout << "----------------" << endl;
54         info.display();
55         cout << "----------------" << endl;
56     }
57 
58     return 0;
59 }

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实验任务七

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

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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 }

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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

View Code

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 }

View Code

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

View Code

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 }

View Code

posted @ 2024-11-24 16:14 张朦丹阅读(2) 评论(0) 编辑收藏举报

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