实验四
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(); 18 void output() const; 19 void sort(bool ascending = false); 20 int min() const; 21 int max() const; 22 float average() const; 23 void info(); 24 25 private: 26 void compute(); 27 28 private: 29 string course_name; 30 int n; 31 vector<int> counts = vector<int>(5,0); 32 vector<double> rates = vector<double>(5,0); 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(); 93 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) << 97 average() << endl; 98 compute(); // 统计各分数段人数、比例 99 vector<string> tmp {"[0, 60) ", "[60, 70)", "[70, 80)","[80, 90)", 100 "[90, 100]" 101 }; 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 << 105 "%" << endl; 106 }
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 }
结果：
问题1：
成绩存在GradeCalc类的vector中；接口：this->begin()、this->end()；input函数通过的接口：this->push_back；
问题2：
算平均数；有影响；“*1.0”可以把一个整数变为浮点数，去掉之后，无法得出小数的结果；
问题3：
没有检验输入数据是否有误（比如，成绩输入应在0-100）；
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 private: 25 void compute(); // 成绩统计 26 private: 27 string course_name; // 课程名 28 int n; // 课程人数 29 vector<int> grades; // 课程成绩 30 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] 31 vector<double> rates = vector<double>(5, 0); // 保存各分数段比例 32 }; 33 GradeCalc::GradeCalc(const string &cname, int size): 34 course_name {cname}, n {size} {} 35 void GradeCalc::input() { 36 int grade; 37 for(int i = 0; i < n; ++i) { 38 cin >> grade; 39 grades.push_back(grade); 40 } 41 } 42 void GradeCalc::output() const { 43 for(int grade: grades) 44 cout << grade << " "; 45 cout << endl; 46 } 47 void GradeCalc::sort(bool ascending) { 48 if(ascending) 49 std::sort(grades.begin(), grades.end()); 50 else 51 std::sort(grades.begin(), grades.end(), std::greater<int>()); 52 } 53 int GradeCalc::min() const { 54 return *std::min_element(grades.begin(), grades.end()); 55 } 56 int GradeCalc::max() const { 57 return *std::max_element(grades.begin(), grades.end()); 58 } 59 float GradeCalc::average() const { 60 return std::accumulate(grades.begin(), grades.end(), 0) * 1.0 / n; 61 } 62 void GradeCalc::compute() { 63 for(int grade: grades) { 64 if(grade < 60) 65 counts.at(0)++; 66 else if(grade >= 60 && grade < 70) 67 counts.at(1)++; 68 else if(grade >= 70 && grade < 80) 69 counts.at(2)++; 70 else if(grade >= 80 && grade < 90) 71 counts.at(3)++; 72 else if(grade >= 90) 73 counts.at(4)++; 74 } 75 for(int i = 0; i < rates.size(); ++i) 76 rates.at(i) = counts.at(i) *1.0 / n; 77 } 78 void GradeCalc::info() { 79 cout << "课程名称:\t" << course_name << endl; 80 cout << "排序后成绩: \t"; 81 sort(); 82 output(); 83 cout << "最高分:\t" << max() << endl; 84 cout << "最低分:\t" << min() << endl; 85 cout << "平均分:\t" << std::fixed << std::setprecision(2) << 86 average() << endl; 87 compute(); // 统计各分数段人数、比例 88 vector<string> tmp {"[0, 60) ", "[60, 70)", "[70, 80)","[80, 90)", 89 "[90, 100]" 90 }; 91 for(int i = tmp.size()-1; i >= 0; --i) 92 cout << tmp[i] << "\t: " << counts[i] << "人\t" 93 << std::fixed << std::setprecision(2) << rates[i]*100 << 94 "%" << endl; 95 }
task3.cpp：
1 #include "GradeCalc.hpp" 2 #include <iomanip> 3 void test() { 4 int n; 5 cout << "输入班级人数: "; 6 cin >> n; 7 GradeCalc c1("OOP", n); 8 cout << "录入成绩: " << endl;; 9 c1.input(); 10 cout << "输出成绩: " << endl; 11 c1.output(); 12 cout << string(20, '*') + "课程成绩信息" + string(20, '*') << endl; 13 c1.info(); 14 } 15 int main() { 16 test(); 17 }
结果：
问题1：
成绩存在vector<int> grades中，通过变量名加“.”来访问；
问题二：
不一定必须要使用集成的方式来实现；
任务四：
task4-1.cpp：
1 #include <iostream> 2 #include <string> 3 #include <limits> 4 using namespace std; 5 void test1() { 6 string s1, s2; 7 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 8 cout << "s1: " << s1 << endl; 9 cout << "s2: " << s2 << endl; 10 } 11 void test2() { 12 string s1, s2; 13 getline(cin, s1); // getline(): 从输入流中提取字符串，直到遇到换行符 14 getline(cin, s2); 15 cout << "s1: " << s1 << endl; 16 cout << "s2: " << s2 << endl; 17 } 18 void test3() { 19 string s1, s2; 20 getline(cin, s1, ' '); //从输入流中提取字符串，直到遇到指定分隔符 21 getline(cin, s2); 22 cout << "s1: " << s1 << endl; 23 cout << "s2: " << s2 << endl; 24 } 25 int main() { 26 cout << "测试1: 使用标准输入流对象cin输入字符串" << endl; 27 test1(); 28 cout << endl; 29 cin.ignore(numeric_limits<streamsize>::max(), '\n'); 30 cout << "测试2: 使用函数getline()输入字符串" << endl; 31 test2(); 32 cout << endl; 33 cout << "测试3: 使用函数getline()输入字符串, 指定字符串分隔符" << endl; 34 test3(); 35 }
结果：
删除后结果：
问题：
避免影响下一次输入
task4-2.cpp：
1 #include <iostream> 2 #include <string> 3 #include <vector> 4 #include <limits> 5 using namespace std; 6 void output(const vector<string> &v) { 7 for(auto &s: v) 8 cout << s << endl; 9 } 10 void test() { 11 int n; 12 while(cout << "Enter n: ", cin >> n) { 13 vector<string> v1; 14 for(int i = 0; i < n; ++i) { 15 string s; 16 cin >> s; 17 v1.push_back(s); 18 } 19 cout << "output v1: " << endl; 20 output(v1); 21 cout << endl; 22 } 23 } 24 int main() { 25 cout << "测试: 使用cin多组输入字符串" << endl; 26 test(); 27 }
task4-3.cpp：
1 #include <iostream> 2 #include <string> 3 #include <vector> 4 #include <limits> 5 using namespace std; 6 void output(const vector<string> &v) { 7 for(auto &s: v) 8 cout << s << endl; 9 } 10 void test() { 11 int n; 12 while(cout << "Enter n: ", cin >> n) { 13 cin.ignore(numeric_limits<streamsize>::max(), '\n'); 14 vector<string> v2; 15 for(int i = 0; i < n; ++i) { 16 string s; 17 getline(cin, s); 18 v2.push_back(s); 19 } 20 cout << "output v2: " << endl; 21 output(v2); 22 cout << endl; 23 } 24 } 25 int main() { 26 cout << "测试: 使用函数getline()多组输入字符串" << endl; 27 test(); 28 }
结果：
删除后结果：
问题：
避免对下依次输入产生影响
任务五：
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 resourse; 10 11 public: 12 GameResourceManager(T res):resourse{res}{} 13 T get() const{ 14 return resourse; 15 } 16 17 void update(T sum){ 18 resourse += sum; 19 if(resourse < 0) 20 resourse = 0; 21 } 22 };
task5.cpp:
1 #include "grm.hpp" 2 #include <iostream> 3 using std::cout; 4 using std::endl; 5 void test1() { 6 GameResourceManager<float> HP_manager(99.99); 7 cout << "当前生命值: " << HP_manager.get() << endl; 8 HP_manager.update(9.99); 9 cout << "增加9.99生命值后, 当前生命值: " << HP_manager.get() << endl; 10 HP_manager.update(-999.99); 11 cout <<"减少999.99生命值后, 当前生命值: " << HP_manager.get() << endl; 12 } 13 void test2() { 14 GameResourceManager<int> Gold_manager(100); 15 cout << "当前金币数量: " << Gold_manager.get() << endl; 16 Gold_manager.update(50); 17 cout << "增加50个金币后, 当前金币数量: " << Gold_manager.get() << endl; 18 Gold_manager.update(-99); 19 cout <<"减少99个金币后, 当前金币数量: " << Gold_manager.get() << endl; 20 } 21 int main() { 22 cout << "测试1: 用float类型对类模板GameResourceManager实例化" << endl; 23 test1(); 24 cout << endl; 25 cout << "测试2: 用int类型对类模板GameResourceManager实例化" << endl; 26 test2(); 27 }
结果：
任务六：
Info.hpp:
1 #include<iostream> 2 #include<iomanip> 3 4 using namespace std; 5 6 class Info { 7 private: 8 string nickname; 9 string contact; 10 string city; 11 int n; 12 public: 13 Info(const string name,const string con, const string place, int num) 14 : nickname(name), contact(con), city(place), n(num) {} 15 16 void display() const { 17 cout << "昵称: " << nickname << endl; 18 cout << "联系方式: " << contact << endl; 19 cout << "所在城市: " << city << endl; 20 cout << "预定参加人数: " << n << endl; 21 } 22 23 24 };
task6.cpp:
1 #include"Info.hpp" 2 3 #include<iostream> 4 #include<vector> 5 #include<string> 6 7 using namespace std; 8 9 int main() { 10 const int capacity = 100; 11 vector<Info> audience_lst; 12 string nickname,contact,city; 13 int n ,sum = 0,i = 0; 14 cout << "录入用户预约信息:" << endl; 15 cout << "昵称" << setw(40) << "联系方式（邮箱/手机号）" << setw(20) << "所在城市" << setw(20) << "预定参加人数" << endl; 16 while(cin >> nickname >> contact >> city >> n) { 17 int s = sum; 18 sum += n; 19 i++; 20 if(nickname == "0") 21 break; 22 else if(sum < 100) { 23 audience_lst.push_back(Info(nickname,contact,city,n)); 24 } else if(sum > 100) { 25 sum = s; 26 i--; 27 cout << "对不起，只剩" <<100- s << "个名额" << endl; 28 cout << "1.输入u,更新（update)信息" << endl; 29 cout << "2.输入q，退出预定" << endl; 30 cout << "你的选择：" << endl; 31 string tem; 32 cin >> tem; 33 if(tem == "u") { 34 cout << "请重新输入预定信息：" << endl; 35 cin >> nickname >> contact >> city >> n; 36 sum += n; 37 i++; 38 audience_lst.push_back(Info(nickname, contact, city, n)); 39 } else break; 40 } else if(sum ==100) { 41 audience_lst.push_back(Info(nickname, contact, city, n)); 42 break; 43 } 44 } 45 cout << "截至目前，一共有" << sum << "位听众预约，预约情况如下：" << endl; 46 int j; 47 for (j = 0; j < i; j++) { 48 audience_lst[j].display(); 49 } 50 return 0; 51 }
结果：
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.
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 }
结果：
