任务2：
GradeCalc.cpp
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: public vector<int> {
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> 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 this->push_back(grade);
44 }
45 }
46
47 void GradeCalc::output() const {
48 for(auto ptr = this->begin(); ptr != this->end(); ++ptr)
49 cout << *ptr << " ";
50 cout << endl;
51 }
52
53 void GradeCalc::sort(bool ascending) {
54 if(ascending)
55 std::sort(this->begin(), this->end());
56 else
57 std::sort(this->begin(), this->end(), std::greater<int>());
58 }
59
60 int GradeCalc::min() const {
61 return *std::min_element(this->begin(), this->end());
62 }
63
64 int GradeCalc::max() const {
65 return *std::max_element(this->begin(), this->end());
66 }
67
68 float GradeCalc::average() const {
69 return std::accumulate(this->begin(), this->end(), 0) * 1.0 / n;
70 }
71
72 void GradeCalc::compute() {
73 for(int grade: *this) {
74 if(grade < 60)
75 counts.at(0)++;
76 else if(grade >= 60 && grade < 70)
77 counts.at(1)++;
78 else if(grade >= 70 && grade < 80)
79 counts.at(2)++;
80 else if(grade >= 80 && grade < 90)
81 counts.at(3)++;
82 else if(grade >= 90)
83 counts.at(4)++;
84 }
85
86 for(int i = 0; i < rates.size(); ++i)
87 rates.at(i) = counts.at(i) * 1.0 / n;
88 }
89
90 void GradeCalc::info() {
91 cout << "课程名称:\t" << course_name << endl;
92 cout << "排序后成绩: \t";
93 sort(); output();
94 cout << "最高分:\t" << max() << endl;
95 cout << "最低分:\t" << min() << endl;
96 cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl;
97
98 compute(); // 统计各分数段人数、比例
99
100 vector<string> tmp{"[0, 60) ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]"};
101 for(int i = tmp.size()-1; i >= 0; --i)
102 cout << tmp[i] << "\t: " << counts[i] << "人\t"
103 << std::fixed << std::setprecision(2) << rates[i]*100 << "%" << endl;
104 }
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：成绩存储在其基类vector类中；通过public继承方式继承的vector类中的接口访问每一个成绩；通过vector类中的push_back接口存入。
问题2：计算vector容器中存储所有元素的平均值；有影响，因为不加1.0时在整除运算会失去小数部分。
问题3：当班级人数输入为0时会导致除数为0，从而发生错误，应该限制输入格式。
任务3：
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：存储在GaradeCalc类的私有成员vector<int> grade中，直接在类内部访问grade。
问题2：通过继承基类可以访问基类中的接口以方便操作。
任务4：
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 }
运行结果：
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1：用 cin.ignore()忽略换行符，使getline() 能正确读取后续用户输入的字符串。
问题2：用 cin.ignore()忽略换行符，使循环能在停止输入(即^Z) 时正确终止。
任务5：
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 public:
11 GameResourceManager(T n) : resource{n} {}
12 T get() const;
13 void update(T n);
14 };
15
16 template<typename T>
17 T GameResourceManager<T>::get() const{
18 return resource;
19 }
20
21 template<typename T>
22 void GameResourceManager<T>::update(T n) {
23 if(resource + n > 0)
24 resource += n;
25 else
26 resource = 0;
27 }
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
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 }
运行结果：
任务6：
Info.hpp
1 #pragma once
2 #include <iostream>
3 #include <string>
4 #include <iomanip>
5
6 using namespace std;
7
8 class Info {
9 private:
10 string nickname;
11 string contact;
12 string city;
13 public:
14 int n;
15 public:
16 Info(string nn , string ct , string c , int N) : nickname{nn} , contact{ct} , city{c} , n{N} {}
17 void display() const;
18 };
19
20 void Info::display() const {
21 cout << left << setw(16) << "昵称:" << left << setw(16) << nickname << endl;
22 cout << left << setw(16) << "联系方式:" << left << setw(16) << contact << endl;
23 cout << left << setw(16) << "所在城市:" << left << setw(16) << city << endl;
24 cout << left << setw(16) << "预定人数:" << left << setw(16) << n << endl;
25 }
task6.cpp
1 #include "Info.hpp"
2 #include <vector>
3
4 using namespace std;
5
6 void test() {
7 string nn , ct , c;
8 int N , count = 0 , n;
9 const int capacity = 100;
10 vector<Info> audience_list;
11 char choose;
12
13 cout << "录入用户预约信息:" << endl;
14 cout << endl;
15 cout << left << setw(16) << "昵称" << left << setw(32) << "联系方式(邮箱/手机号)" << left << setw(16) << "所在城市" << left << setw(16) << "预定参加人数" <<endl;
16 while(count != capacity) {
17 cin >> nn;
18 if(nn == "stop")
19 break;
20 cin >> ct >> c >> N ;
21 Info I(nn , ct , c , N);
22 if(count < capacity) {
23 audience_list.push_back(I);
24 count += N;
25 }
26 if(count > capacity){
27 count -= N;
28 audience_list.pop_back();
29 cout << "对不起，只剩" << capacity - count << "个位置." << endl;
30 cout << "1. 输入u，更新(update)预定信息" << endl;
31 cout << "2. 输入q，退出预定" << endl;
32 cout << "你的选择: ";
33 cin >> choose;
34 if(choose == 'u') {
35 cout << "请重新输入预定信息:" << endl;
36 cin >> nn >> ct >> c >> N ;
37 Info I(nn , ct , c ,N);
38 audience_list.push_back(I);
39 count += N;
40 }
41 else if(choose == 'q')
42 break;
43 }
44 }
45 cout << endl;
46 cout << "截至目前，一共有" << count << "位听众预约。预约听众信息如下:" << endl;
47 cout << "-----------------------------------" << endl;
48 for(auto i : audience_list) {
49 i.display();
50 cout << "-----------------------------------" << endl;
51 }
52 }
53
54 int main() {
55 test();
56 }
运行结果：
1.
2.
任务7：
date.h 1 #pragma once
2
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 int distance(const Date& date)const {
20 return totalDays-date.totalDays;
21 }
22 };
date.cpp
1 #include"date.h"
2 #include<iostream>
3 #include<cstdlib>
4
5 using namespace std;
6
7 namespace {
8 const int DAYS_BEFIRE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304 ,334,365 };
9 }
10 Date::Date(int year, int month, int day) :year(year), month(month), day(day) {
11 if (day<= 0 || day>getMaxDay()) {
12 cout<<"Invalid date: ";
13 show();
14 cout<<endl;
15 exit(1);
16 }
17 int years=year-1;
18 totalDays=years*365+years/4-years/100+years/400+DAYS_BEFIRE_MONTH[month-1]+day;
19 if (isLeapYear() && month>2) totalDays++;
20 }
21 int Date::getMaxDay() const {
22 if (isLeapYear() &&month==2)
23 return 29;
24 else return DAYS_BEFIRE_MONTH[month]-DAYS_BEFIRE_MONTH[month-1];
25 }
26 void Date::show()const {
27 cout<<getYear()<<"-"<<getMonth()<<"-"<<getDay();
28 }
accumulator.h
1 #include "date.h"
2 class Accumulator {
3 private:
4 Date lastDate;
5 double value;
6 double sum;
7 public:
8 Accumulator(const Date &date , double value) : lastDate{date} , value{value} , sum{0} {}
9 double getSum(const Date &date) const {
10 return sum + value * date.distance(lastDate);
11 }
12 void change(const Date &date , double value) {
13 sum = getSum(date);
14 lastDate = date;
15 this->value = value;
16 }
17 void reset(const Date &date , double value) {
18 lastDate = date;
19 this->value = value;
20 sum = 0;
21 }
22 };
account.h
1 #include "date.h"
2 #include "accumulator.h"
3 #include <string>
4
5 using namespace std;
6
7 class Account {
8 private:
9 string id;
10 double balance;
11 static double total;
12 protected:
13 Account(const Date &date , const string &id);
14 void record(const Date &date , double amount , const string &desc);
15 void error(const string &msg) const;
16 public:
17 const string getId() const {return id;}
18 double getBalance() const {return balance;}
19 static double getTotal() {return total;}
20 void show() const;
21 };
22 class SavingsAccount:public Account {
23 private:
24 Accumulator acc;
25 double rate;
26 public:
27 SavingsAccount(const Date& date , const string& id , double rate);
28 double getRate() const {return rate;}
29 void deposit(const Date& date , double amount , const string& desc);
30 void withdraw(const Date& date , double amount , const string& desc);
31 void settle(const Date& date);
32 };
33 class CreditAccount :public Account {
34 private:
35 Accumulator acc;
36 double credit;
37 double rate;
38 double fee;
39 double getDebt() const {
40 double balance = getBalance();
41 return(balance < 0 ? balance : 0);
42 }
43 public:CreditAccount(const Date& date , const string& id , double credit , double rate , double fee);
44 double getCredit() const {return credit;}
45 double getRate() const {return rate;}
46 double getFee() const {return fee;}
47 double getAvailableCredit() const {
48 if (getBalance() < 0) return credit + getBalance();
49 else return credit;
50 }
51 void deposit(const Date& date , double amount , const string& desc);
52 void withdraw(const Date& date , double amount , const string& desc);
53 void settle(const Date& date);
54 void show() const;
55 };
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 }
7_10.cpp
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 }
运行结果：
总结：
1. 定义了一个基类account，继承基类得到了两个派生类SavingAccounts和CreditAccounts。
2.重新定义了一个类accumulator用于计算银行账户存款的积累.
标签：const,int,void,C++,Date,实验,date,include From： https://www.cnblogs.com/tt3n/p/18553095