task2：
代码：
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
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
截图：
问题1：
成绩存储在：通过this指针存在push_back（grade）中；通过this指针进行访问
问题2：
作用：对于班级总成绩进行求平均，同时明确输出的平均值为float型数据，没有影响，作用是将整型的总成绩变为浮点型数据
问题3：
对于各分数段成绩的统计，对于总分不同的成绩统计不太适用
task3：
代码：
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
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
截图：
问题1：
直接存储到了<vector>grades 当中；
是通过grades直接访问，减少了对this->指针的使用
问题2：
实验三对于成绩的存储，直接选用增加一个<vector>grades直接存入成绩，更加方便，直接
task4.1:
代码：
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
截图：
问题1：作用：防止test1最后输入的换行操作对test2产生影响。
task4.2:
代码：
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
截图：
task4.3：
代码：
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
截图：
问题：
用途：消除上一次测试对本次测试的影响。
task 5:
代码：
1 hppView Code
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
task6:
代码：
1 hpp
2 #pragma once
3 #include<iostream>
4 #include<iomanip>
5 using namespace std;
6 class Info {
7 public:
8 string nickname;
9 string contact;
10 string city;
11 int n;
12 public:
13 Info(string nickname_,string contact_,string city_,int n_):nickname(nickname_),contact(contact_),city(city_), n(n_) {}
14 void display()const {
15 cout << string(40, '*') << endl;
16 cout << "昵称:" << "\t" << nickname << endl;
17 cout << "联系方式:" << "\t" << contact << endl;
18 cout << "所在城市:" << "\t" << city << endl;
19 cout << "预定人数:" << "\t" << n << endl;
20 }
21 };
View Code
1 cpp
2 #include"Info.hpp"
3 #include<iomanip>
4 #include<vector>
5 const int capacity = 100;
6 int main() {
7 cout << "录入用户预约信息:" << endl;
8 cout << "录入用户数:";
9 int n;
10 cin >> n;
11 cout << "昵称" << "\t" << "联系方式(邮箱/手机号)" << "\t" << "所在城市" << "\t" << "预定参加人数" << endl;
12 vector<Info> v;
13 string nickname;
14 string contact;
15 string city;
16 int num;
17 int sum = 0;
18 for (int i = 0; i < n; i++) {
19 cin >> nickname >> contact >> city >> num;
20 sum += num;
21 if (sum > capacity) {
22 char choice;
23 cout << "对不起，只剩" << 100 + num - sum << "个位置" << endl;
24 cout << "1. 输入u,更新(update)预定信息" << endl;
25 cout << "2. 输入q,退出预定" << endl;
26 cout << "你的选择: ";
27 cin >> choice;
28 if (choice == 'u') {
29 sum -= num;
30 cout << "请重新输入预定信息" << endl;
31 cin >> nickname >> contact >> city >> num;
32 sum += num;
33 }
34 else if(choice=='q') {
35 continue;
36 }
37 }
38 v.push_back(Info(nickname, contact, city, num));
39 }
40 cout << "截至目前,一共有" << sum << "位听众预约。" << "预约听众信息如下:" << endl;
41 for (auto i : v) {
42 i.display();
43 }
44 cout << string(40, '*');
45 return 0;
46 }
View Code
截图：
task7:
代码：
1 date.h
2 #pragma once
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 };
23 accumulator.h
24 #pragma once
25 #include "date.h"
26 class Accumulator {
27 private:
28 Date lastDate;
29 double value;
30 double sum;
31 public:
32 Accumulator(const Date&date,double value):lastDate(date),value(value),sum{0}{}
33 double getSum(const Date& date) const {
34 return sum + value * date.distance(lastDate);
35 }
36 void change(const Date& date, double value) {
37 sum = getSum(date);
38 lastDate = date;
39 this->value = value;
40 }
41 void reset(const Date& date, double value) {
42 lastDate = date;
43 this->value;
44 sum = 0;
45 }
46 };
47 account.h
48 #pragma once
49 #include"date.h"
50 #include"accumulator.h"
51 #include<string>
52 using namespace std;
53 class Account {
54 private:
55 string id;
56 double balance;
57 static double total;
58 protected:
59 Account(const Date& date, const string &id);
60 void record(const Date& date, double amount, const string& desc);
61 void error(const string& msg) const;
62 public:const string& getId() { return id; }
63 double getBalance()const { return balance; }
64 static double getTotal() { return total; }
65 void show()const;
66 };
67 class SavingsAccount:public Account {
68 private:
69 Accumulator acc;
70 double rate;
71 public:
72 SavingsAccount(const Date& date, const string& id, double rate);
73 double getRate() const { return rate; }
74 void deposit(const Date& date, double amount, const string& desc);
75 void withdraw(const Date& date, double amount, const string& desc);
76 void settle(const Date& date);
77 };
78 class CreditAccount :public Account {
79 private:
80 Accumulator acc;
81 double credit;
82 double rate;
83 double fee;
84 double getDebt()const {
85 double balance = getBalance();
86 return(balance < 0 ? balance : 0);
87 }
88 public:CreditAccount(const Date& date, const string& id, double credit, double rate, double fee);
89 double getCredit()const { return credit; }
90 double getRate()const { return rate; }
91 double getFee() const { return fee; }
92 double getAvailableCredit()const {
93 if (getBalance() < 0)return credit + getBalance();
94 else return credit;
95 }
96 void deposit(const Date& date, double amount, const string& desc);
97 void withdraw(const Date& date, double amount, const string& desc);
98 void settle(const Date& date);
99 void show()const;
100 };
101
102 date.cpp
103 #include"date.h"
104 #include<iostream>
105 #include<cstdlib>
106 using namespace std;
107 namespace {
108 const int DAYS_BEFIRE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304 ,334,365 };
109 }
110 Date::Date(int year, int month, int day) :year(year), month(month), day(day) {
111 if (day <= 0 || day > getMaxDay()) {
112 cout << "Invalid date: ";
113 show();
114 cout << endl;
115 exit(1);
116 }
117 int years = year - 1;
118 totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFIRE_MONTH[month - 1] + day;
119 if (isLeapYear() && month > 2) totalDays++;
120 }
121 int Date::getMaxDay()const {
122 if (isLeapYear() && month == 2)
123 return 29;
124 else return DAYS_BEFIRE_MONTH[month] - DAYS_BEFIRE_MONTH[month - 1];
125 }
126 void Date::show()const {
127 cout << getYear() << "-" << getMonth() << "-" << getDay();
128 }
129
130 accumulator.cpp
131 #include "account.h"
132 #include <cmath>
133 #include<iostream>
134 using namespace std;
135 double Account::total = 0;
136 Account::Account(const Date& date, const string& id) :id(id), balance(0) {
137 date.show();
138 cout << "\t#" << id << "created" << endl;
139 }
140 void Account::record(const Date& date, double amount, const string& desc) {
141 amount = floor(amount * 100 + 0.5) / 100;
142 balance += amount;
143 total += amount;
144 date.show();
145 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
146 }
147 void Account::show()const { cout << id << "\tBalance:" << balance; }
148 void Account::error(const string& msg)const {
149 cout << "Error(#" << id << "):" << msg << endl;
150 }
151 SavingsAccount::SavingsAccount(const Date&date,const string &id,double rate):Account(date,id),rate(rate),acc(date,0){}
152 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
153 record(date, amount, desc);
154 acc.change(date, getBalance());
155 }
156 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
157 if (amount > getBalance()) {
158 error("not enough money");
159 }
160 else {
161 record(date, -amount, desc);
162 acc.change(date, getBalance());
163 }
164 }
165 void SavingsAccount::settle(const Date& date) {
166 double interest = acc.getSum(date) * rate/date.distance(Date(date.getYear()-1,1,1));
167 if (interest != 0)record(date, interest, "interest");
168 acc.reset(date, getBalance());
169 }
170 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){}
171 void CreditAccount::deposit(const Date& date, double amount, const string& desc) {
172 record(date, amount, desc);
173 acc.change(date, getDebt());
174 }
175 void CreditAccount::withdraw(const Date& date, double amount, const string& desc) {
176 if (amount - getBalance() > credit) {
177 error("not enouogh credit");
178 }
179 else {
180 record(date, -amount, desc);
181 acc.change(date, getDebt());
182 }
183 }
184 void CreditAccount::settle(const Date& date) {
185 double interest = acc.getSum(date) * rate;
186 if (interest != 0) record(date, interest, "interest");
187 if (date.getMonth() == 1)record(date, -fee, "annual fee");
188 acc.reset(date, getDebt());
189 }
190 void CreditAccount::show()const {
191 Account::show();
192 cout << "\tAvailable credit:" << getAvailableCredit();
193 }
194 task7.cpp
195 #include "account.h"
196 #include<iostream>
197 using namespace std;
198 int main() {
199 Date date(2008, 11, 1);
200 SavingsAccount sa1(date, "S3755217", 0.015);
201 SavingsAccount sa2(date, "02342342", 0.015);
202 CreditAccount ca(date, "C5392394", 10000, 0.0005, 50);
203 sa1.deposit(Date(2008, 11, 5), 5000, "Salary");
204 ca.withdraw(Date(2008, 11, 15), 2000, "buy a cell");
205 sa2.deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
206 ca.settle(Date(2008, 12, 1));
207 ca.deposit(Date(2008, 12,1), 2016, "repay the credit");
208 sa1.deposit(Date(2008, 12, 5), 5500, "salary");
209 sa1.settle(Date(2009, 1, 1));
210 sa2.settle(Date(2009, 1, 1));
211 ca.settle(Date(2009, 1, 1));
212 cout << endl;
213 sa1.show(); cout << endl;
214 sa2.show(); cout << endl;
215 ca.show(); cout << endl;
216 cout << "Total: " << Account::getTotal() << endl;
217 return 0;
218
219 }
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问题：运用类的派生，提高代码复用性
标签：const,组合,继承,void,Date,int,date,include,模板 From： https://www.cnblogs.com/nofear77/p/18553235