实验4 类的组合、继承、模板类、标准库

实验任务2:
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
task2.cpp源码:
 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 }
View Code
运行测试截图:
问题1：派生类GradeCalc定义中，成绩存储在哪里？派生类方法sort, min, max, average,
output都要访问成绩，是通过什么接口访问到每个成绩的？input方法是通过什么接口实现数
据存入对象的？
 GradeCalc 对象内部有一个 vector<int> 的数据成员，用于存储成绩。
通过 this 指针访问成绩。
input 方法通过 this->push_back(grade) 将成绩添加到 GradeCalc 对象中。
 
问题2：代码line68分母的功能是？去掉乘以1.0代码，重新编译、运行，结果有影响吗？为什
么要乘以1.0？
 计算所占百分比，无法求出人数百分比，改变数据的类型，由整型变为浮点型。
 
问题3：从真实应用场景角度考虑，GradeCalc类在设计及代码实现细节上，有哪些地方尚未
考虑周全，仍需继续迭代、完善？
判断输入成绩是否合法，不能对学生多课程进行处理。 
 
实验任务3:
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 }
View Code
task3.cpp源码:
 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 }
View Code
运行测试截图:
问题1：组合类GradeCalc定义中，成绩存储在哪里？组合类方法sort, min, max, average,
output都要访问成绩，是通过什么访问到每一个成绩的？观察与实验任务2在代码写法细节上
的差别。

在组合类GradeCalc的定义中，成绩存储在私有成员变量vector<int> grades中。

组合类方法sort, min, max, average, output都需要访问这些成绩，它们通过直接访问grades向量来实现。

 
问题2：对比实验任务2和实验任务3，主体代码逻辑（测试代码）没有变更，类GradeCalc的
接口也没变，变化的是类GradeCalc的设计及接口内部实现细节。你对面向对象编程有什么新
的理解和领悟吗
类设计的区别 
 
实验任务4:
task4_1.cpp源码:
 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 }
View Code
运行测试截图:
task4_2.cpp源码:
 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 }
View Code
运行测试截图:
task4_3.cpp源码:
 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 }
View Code
运行测试截图:
 
问题1：去掉task4_1.cpp的line35，重新编译、运行，给出此时运行结果截图。查阅资料，回
答line35在这里的用途是什么？

忽略输入流cin中从当前位置开始直到下一个换行符（包括换行符本身）的所有字符，或者忽略最多numeric_limits<streamsize>::max()个字符，以先到者为准。这通常用于清除输入缓冲区中的残留字符，特别是在处理连续输入时，避免前一次输入的换行符或多余字符影响到下一次输入。

 
问题2：去掉task4_3.cpp的line16，重新编译、运行，给出此时运行结果。查阅资料，回答
line16在这里的用途是什么？
 忽略输入流中从当前位置开始直到下一个换行符（包括换行符本身）的所有字符，或者忽略最多numeric_limits<streamsize>::max()个字符（以先到者为准）。这个语句在处理连续输入时非常有用，可以避免输入流中的残留字符对后续输入造成影响。
 
实验任务5:
grm.hpp源码:
 1 #pragma once
 2 #ifndef GRM_HPP
 3 #define GRM_HPP
 4 
 5 #include <limits>
 6 
 7 template <typename T>
 8 class GameResourceManager {
 9 private:
10     T resource;
11 
12 public:
13     // 带参数的构造函数，初始化当前资源数量
14     GameResourceManager(T initial_resource) : resource(initial_resource) {}
15 
16     // 获取当前的资源数量
17     T get() const {
18         return resource;
19     }
20 
21     // 更新当前的资源数量（增加、减少），当资源数量减少到<0时，则归0
22     void update(T delta) {
23         resource += delta;
24         if (resource < 0) {
25             resource = 0;
26         }
27     }
28 };
29 
30 #endif // GRM_HPP
View Code
task5.cpp源码:
 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 }
View Code
运行测试截图:
实验任务6:
info.hpp源码:
 1 #pragma once
 2 #ifndef INFO_HPP
 3 #define INFO_HPP
 4 
 5 #include <iostream>
 6 #include <string>
 7 
 8 class Info {
 9 private:
10     std::string nickname;
11     std::string contact;
12     std::string city;
13     int n;
14 
15 public:
16     // 带参数的构造函数
17     Info(std::string nick, std::string cont, std::string cit, int num)
18         : nickname(nick), contact(cont), city(cit), n(num) {}
19 
20     // 显示信息
21     void display() const {
22         std::cout << "昵称: " << nickname << "\n"
23             << "联系方式: " << contact << "\n"
24             << "所在城市: " << city << "\n"
25             << "预定参加人数: " << n << "\n";
26     }
27 };
28 
29 #endif // INFO_HPP
View Code
task6.cpp源码:
 1 #include <iostream>
 2 #include <vector>
 3 #include <string>
 4 #include "info.hpp"
 5 
 6 const int capacity = 100;
 7 
 8 int main() {
 9     std::vector<Info> audience_lst;
10     int remaining_capacity = capacity;
11     std::string nickname, contact, city;
12     int n;
13 
14     std::cout << "请输入预约信息（按Ctrl+Z结束输入或人数达到上限时提示）：\n";
15 
16     while (true) {
17         std::cout << "昵称: ";
18         std::cin >> nickname;
19         std::cout << "联系方式: ";
20         std::cin >> contact;
21         std::cout << "所在城市: ";
22         std::cin >> city;
23         std::cout << "预定参加人数: ";
24         std::cin >> n;
25 
26         if (n > remaining_capacity) {
27             std::cout << "预定人数超过场地剩余容量，请输入q退出预定或输入u更新预定信息。\n";
28             char choice;
29             std::cin >> choice;
30             if (choice == 'q') {
31                 break;
32             }
33             else if (choice == 'u') {
34                 continue; // 重新输入预定信息
35             }
36             else {
37                 std::cout << "无效选择，请重新输入。\n";
38                 continue;
39             }
40         }
41         else {
42             audience_lst.emplace_back(nickname, contact, city, n);
43             remaining_capacity -= n;
44             if (remaining_capacity <= 0 || std::cin.eof()) {
45                 break;
46             }
47         }
48     }
49 
50     std::cout << "\n预约参加livehouse的听众信息：\n";
51     for (const auto& info : audience_lst) {
52         info.display();
53         std::cout << "----------------------------\n";
54     }
55 
56     return 0;
57 }
View Code
运行测试截图:
实验任务7:
date.h:
 1 #pragma once
 2 class Date {
 3 private:
 4     int year;
 5     int month;
 6     int day;
 7     int totalDays;
 8 public:
 9     Date(int year, int month, int day);
10     int getYear()const { return year; }
11     int getMonth()const { return month; }
12     int getDay()const { return day; }
13     int getMaxDay()const;
14     bool isLeapYear()const {
15         return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
16     }
17     void show() const;
18     int distance(const Date& date)const {
19         return totalDays - date.totalDays;
20     }
21 };
View Code
date.cpp:
 1 #pragma once
 2 #include"date.h"
 3 #include"accumulator.h"
 4 #include<string>
 5 using namespace std;
 6 class Account {
 7 private:
 8     string id;
 9     double balance;
10     static double total;
11 protected:
12     Account(const Date& date, const string &id);
13     void record(const Date& date, double amount, const string& desc);
14     void error(const string& msg) const;
15 public:const string& getId() { return id; }
16       double getBalance()const { return balance; }
17       static double getTotal() { return total; }
18       void show()const;
19 };
20 class SavingsAccount:public Account {
21 private:
22     Accumulator acc;
23     double rate;
24 public:
25     SavingsAccount(const Date& date, const string& id, double rate);
26     double getRate() const { return  rate; }
27     void deposit(const Date& date, double amount, const string& desc);
28     void withdraw(const Date& date, double amount, const string& desc);
29     void settle(const Date& date);
30 };
31 class CreditAccount :public Account {
32 private:
33     Accumulator acc;
34     double credit;
35     double rate;
36     double fee;
37     double getDebt()const {
38         double balance = getBalance();
39         return(balance < 0 ? balance : 0);
40     }
41 public:CreditAccount(const Date& date, const string& id, double credit, double rate, double fee);
42       double getCredit()const { return credit; }
43       double getRate()const { return rate; }
44       double getFee() const { return fee; }
45       double getAvailableCredit()const {
46           if (getBalance() < 0)return credit + getBalance();
47           else return credit;
48       }
49       void deposit(const Date& date, double amount, const string& desc);
50       void withdraw(const Date& date, double amount, const string& desc);
51       void settle(const Date& date);
52       void show()const;
53 };
View Code
accumulator.h:
 1 #pragma once
 2 #include "date.h"
 3 class Accumulator {
 4 private:
 5     Date lastDate;
 6     double value;
 7     double sum;
 8 public:
 9     Accumulator(const Date&date,double value):lastDate(date),value(value),sum{0}{}
10     double getSum(const Date& date) const {
11         return sum + value * date.distance(lastDate);
12     }
13     void change(const Date& date, double value) {
14         sum = getSum(date);
15         lastDate = date;
16         this->value = value;
17     }
18     void reset(const Date& date, double value) {
19         lastDate = date;
20         this->value;
21         sum = 0;
22     }
23 };
View Code
account.h:
 1 #pragma once
 2 #include"date.h"
 3 #include"accumulator.h"
 4 #include<string>
 5 using namespace std;
 6 class Account {
 7 private:
 8     string id;
 9     double balance;
10     static double total;
11 protected:
12     Account(const Date& date, const string &id);
13     void record(const Date& date, double amount, const string& desc);
14     void error(const string& msg) const;
15 public:const string& getId() { return id; }
16       double getBalance()const { return balance; }
17       static double getTotal() { return total; }
18       void show()const;
19 };
20 class SavingsAccount:public Account {
21 private:
22     Accumulator acc;
23     double rate;
24 public:
25     SavingsAccount(const Date& date, const string& id, double rate);
26     double getRate() const { return  rate; }
27     void deposit(const Date& date, double amount, const string& desc);
28     void withdraw(const Date& date, double amount, const string& desc);
29     void settle(const Date& date);
30 };
31 class CreditAccount :public Account {
32 private:
33     Accumulator acc;
34     double credit;
35     double rate;
36     double fee;
37     double getDebt()const {
38         double balance = getBalance();
39         return(balance < 0 ? balance : 0);
40     }
41 public:CreditAccount(const Date& date, const string& id, double credit, double rate, double fee);
42       double getCredit()const { return credit; }
43       double getRate()const { return rate; }
44       double getFee() const { return fee; }
45       double getAvailableCredit()const {
46           if (getBalance() < 0)return credit + getBalance();
47           else return credit;
48       }
49       void deposit(const Date& date, double amount, const string& desc);
50       void withdraw(const Date& date, double amount, const string& desc);
51       void settle(const Date& date);
52       void show()const;
53 };
View Code
account.cpp:
 1 #include "account.h"
 2 #include <cmath>
 3 #include<iostream>
 4 using namespace std;
 5 double Account::total = 0;
 6 Account::Account(const Date& date, const string& id) :id(id), balance(0) {
 7     date.show();
 8     cout << "\t#" << id << "created" << endl;
 9 }
10 void Account::record(const Date& date, double amount, const string& desc) {
11     amount = floor(amount * 100 + 0.5) / 100;
12     balance += amount;
13     total += amount;
14     date.show();
15     cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
16 }
17 void Account::show()const { cout << id << "\tBalance:" << balance; }
18 void Account::error(const string& msg)const {
19     cout << "Error(#" << id << "):" << msg << endl;
20 }
21 SavingsAccount::SavingsAccount(const Date&date,const string &id,double rate):Account(date,id),rate(rate),acc(date,0){}
22 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
23     record(date, amount, desc);
24     acc.change(date, getBalance());
25 }
26 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
27     if (amount > getBalance()) {
28         error("not enough money");
29     }
30     else {
31         record(date, -amount, desc);
32         acc.change(date, getBalance());
33     }
34 }
35 void SavingsAccount::settle(const Date& date) {
36     double interest = acc.getSum(date) * rate/date.distance(Date(date.getYear()-1,1,1));
37     if (interest != 0)record(date, interest, "interest");
38     acc.reset(date, getBalance());
39 }
40 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){}
41 void CreditAccount::deposit(const Date& date, double amount, const string& desc) {
42     record(date, amount, desc);
43     acc.change(date, getDebt());
44 }
45 void CreditAccount::withdraw(const Date& date, double amount, const string& desc) {
46     if (amount - getBalance() > credit) {
47         error("not enouogh credit");
48     }
49     else {
50         record(date, -amount, desc);
51         acc.change(date, getDebt());
52     }
53 }
54 void CreditAccount::settle(const Date& date) {
55     double interest = acc.getSum(date) * rate;
56     if (interest != 0) record(date, interest, "interest");
57     if (date.getMonth() == 1)record(date, -fee, "annual fee");
58     acc.reset(date, getDebt());
59 }
60 void CreditAccount::show()const {
61     Account::show();
62     cout << "\tAvailable credit:" << getAvailableCredit();
63 }
View Code
7_10.cpp源码:
 1 #include "account.h"
 2 #include<iostream>
 3 using namespace std;
 4 int main() {
 5     Date date(2008, 11, 1);
 6     SavingsAccount sa1(date, "S3755217", 0.015);
 7     SavingsAccount sa2(date, "02342342", 0.015);
 8     CreditAccount ca(date, "C5392394", 10000, 0.0005, 50);
 9     sa1.deposit(Date(2008, 11, 5), 5000, "Salary");
10     ca.withdraw(Date(2008, 11, 15), 2000, "buy a cell");
11     sa2.deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
12     ca.settle(Date(2008, 12, 1));
13     ca.deposit(Date(2008, 12,1), 2016, "repay the credit");
14     sa1.deposit(Date(2008, 12, 5), 5500, "salary");
15     sa1.settle(Date(2009, 1, 1));
16     sa2.settle(Date(2009, 1, 1));
17     ca.settle(Date(2009, 1, 1));
18     cout << endl;
19     sa1.show(); cout << endl;
20     sa2.show(); cout << endl;
21     ca.show(); cout << endl;
22     cout << "Total: " << Account::getTotal() << endl;
23     return 0;
24 
25 }
View Code
运行测试截图:
 
 
 
 
 
posted @ 2024-11-23 15:00  雪藏的熊  阅读(10)  评论(0)  编辑  收藏  举报