实验4 类的组合、继承、模板类、标准库

1.实验二：

GradeCalc.hpp

#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<numeric>
#include<iomanip>

using std::vector;
using std::string;
using std::cin;
using std::cout;
using std::endl;

class GradeCalc : public vector<int> {
public:
    GradeCalc(const string& cname, int size);
    void input();// 录入成绩
    void output() const;//输出成绩
    void sort(bool ascending = false);//排序（默认降序）
    int min() const;//返回最低分
    int max() const;//返回最高分
    float average() const;//返回平均分
    void info();//输出课程成绩信息

private:
    void compute();

private:
    string course_name;
    int n;
    vector<int>counts = vector<int>(5, 0);//保存各分数段人数
    vector<double>rates = vector<double>(5, 0);//保存各分数段比例
};

GradeCalc::GradeCalc(const string& cname, int size) : course_name{ cname }, n{ size } {}

void GradeCalc::input() {
    int grade;

    for (int i = 0; i < n; ++i) {
        cin >> grade;
        this->push_back(grade);
    }
}

void GradeCalc::output() const {
    for (auto ptr = this->begin(); ptr != this->end(); ++ptr)
        cout << *ptr << " ";
    cout << endl;
}

void GradeCalc::sort(bool ascending) {
    if (ascending)
        std::sort(this->begin(), this->end());
    else
        std::sort(this->begin(), this->end(), std::greater<int>());
}

int GradeCalc::min() const {
    return *std::min_element(this->begin(), this->end());
}

int GradeCalc::max() const {
    return *std::max_element(this->begin(), this->end());
}

float GradeCalc::average() const {
    return std::accumulate(this->begin(), this->end(), 0) * 1.0 / n;
}

void GradeCalc::compute() {
    for (int grade : *this) {
        if (grade < 60)
            counts.at(0)++;
        else if (grade >= 60 && grade < 70)
            counts.at(1)++;
        else if (grade >= 70 && grade < 80)
            counts.at(2)++;
        else if (grade >= 80 && grade < 90)
            counts.at(3)++;
        else if (grade >= 90)
            counts.at(4)++;
    }

    for (int i = 0; i < rates.size(); ++i)
        rates.at(i) = counts.at(i) * 1.0 / n;
}

void GradeCalc::info() {
    cout << "课程名称:\t" << course_name << endl;
    cout << "排序后成绩: \t";
    sort();  output();
    cout << "最高分:\t" << max() << endl;
    cout << "最低分:\t" << min() << endl;
    cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl;

    compute();  // 统计各分数段人数、比例

    vector<string> tmp{ "[0, 60)  ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]" };
    for (int i = tmp.size() - 1; i >= 0; --i)
        cout << tmp[i] << "\t: " << counts[i] << "人\t"
        << std::fixed << std::setprecision(2) << rates[i] * 100 << "%" << endl;
}

test.cpp

#include "GradeCalc.hpp"
#include <iomanip>

void test() {
    int n;
    cout << "输入班级人数: ";
    cin >> n;

    GradeCalc c1("OOP", n);

    cout << "录入成绩: " << endl;;
    c1.input();
    cout << "输出成绩: " << endl;
    c1.output();

    cout << string(20, '*') + "课程成绩信息" + string(20, '*') << endl;
    c1.info();
}

int main() {
    test();
}

运行结果截图

问题1：

成绩存储在 vector<int>；通过 this 指针；通过 this->push_back(grade) 

问题2：

计算百分比，将数据类型改变成浮点型

问题3：

可以判断录入成绩是否合法

2.实验3：

GradeCalc.hpp

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iomanip>

using std::vector;
using std::string;
using std::cin;
using std::cout;
using std::endl;

class GradeCalc {
public:
    GradeCalc(const string& cname, int size);
    void input();                             // 录入成绩
    void output() const;                      // 输出成绩
    void sort(bool ascending = false);        // 排序 (默认降序)
    int min() const;                          // 返回最低分
    int max() const;                          // 返回最高分
    float average() const;                    // 返回平均分
    void info();                              // 输出课程成绩信息 

private:
    void compute();     // 成绩统计

private:
    string course_name;     // 课程名
    int n;                  // 课程人数
    vector<int> grades;     // 课程成绩
    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]
    vector<double> rates = vector<double>(5, 0); // 保存各分数段比例 
};

GradeCalc::GradeCalc(const string& cname, int size) : course_name{ cname }, n{ size } {}

void GradeCalc::input() {
    int grade;

    for (int i = 0; i < n; ++i) {
        cin >> grade;
        grades.push_back(grade);
    }
}

void GradeCalc::output() const {
    for (int grade : grades)
        cout << grade << " ";
    cout << endl;
}

void GradeCalc::sort(bool ascending) {
    if (ascending)
        std::sort(grades.begin(), grades.end());
    else
        std::sort(grades.begin(), grades.end(), std::greater<int>());

}

int GradeCalc::min() const {
    return *std::min_element(grades.begin(), grades.end());
}

int GradeCalc::max() const {
    return *std::max_element(grades.begin(), grades.end());
}

float GradeCalc::average() const {
    return std::accumulate(grades.begin(), grades.end(), 0) * 1.0 / n;
}

void GradeCalc::compute() {
    for (int grade : grades) {
        if (grade < 60)
            counts.at(0)++;
        else if (grade >= 60 && grade < 70)
            counts.at(1)++;
        else if (grade >= 70 && grade < 80)
            counts.at(2)++;
        else if (grade >= 80 && grade < 90)
            counts.at(3)++;
        else if (grade >= 90)
            counts.at(4)++;
    }

    for (int i = 0; i < rates.size(); ++i)
        rates.at(i) = counts.at(i) * 1.0 / n;
}

void GradeCalc::info() {
    cout << "课程名称:\t" << course_name << endl;
    cout << "排序后成绩: \t";
    sort();  output();
    cout << "最高分:\t" << max() << endl;
    cout << "最低分:\t" << min() << endl;
    cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl;

    compute();  // 统计各分数段人数、比例

    vector<string> tmp{ "[0, 60)  ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]" };
    for (int i = tmp.size() - 1; i >= 0; --i)
        cout << tmp[i] << "\t: " << counts[i] << "人\t"
        << std::fixed << std::setprecision(2) << rates[i] * 100 << "%" << endl;
}

test.cpp

#include "GradeCalc.hpp"
#include <iomanip>

void test() {
    int n;
    cout << "输入班级人数: ";
    cin >> n;

    GradeCalc c1("OOP", n);

    cout << "录入成绩: " << endl;;
    c1.input();
    cout << "输出成绩: " << endl;
    c1.output();

    cout << string(20, '*') + "课程成绩信息" + string(20, '*') << endl;
    c1.info();
}

int main() {
    test();
}

运行代码截图

问题1：存储在私有成员变量vector<int> grades；；通过直接访问grades

问题2：通过grades实现了更加方便的访问

3.实验4：

4.1.cpp

#include <iostream>
#include <string>
#include <limits>

using namespace std;

void test1() {
    string s1, s2;
    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
    cout << "s1: " << s1 << endl;
    cout << "s2: " << s2 << endl;
}

void test2() {
    string s1, s2;
    getline(cin, s1);  // getline(): 从输入流中提取字符串，直到遇到换行符
    getline(cin, s2);
    cout << "s1: " << s1 << endl;
    cout << "s2: " << s2 << endl;
}

void test3() {
    string s1, s2;
    getline(cin, s1, ' '); //从输入流中提取字符串，直到遇到指定分隔符
    getline(cin, s2);
    cout << "s1: " << s1 << endl;
    cout << "s2: " << s2 << endl;
}

int main() {
    cout << "测试1: 使用标准输入流对象cin输入字符串" << endl;
    test1();
    cout << endl;

    cin.ignore(numeric_limits<streamsize>::max(), '\n');

    cout << "测试2: 使用函数getline()输入字符串" << endl;
    test2();
    cout << endl;

    cout << "测试3: 使用函数getline()输入字符串, 指定字符串分隔符" << endl;
    test3();
}

运行结果截图：

问题1：

运行结果截图：

问题1：

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 避免前一次输入的换行符或多余字符影响到下一次输入

4.2.cpp

#include <iostream>
#include <string>
#include <vector>
#include <limits>

using namespace std;

void output(const vector<string> &v) {
    for(auto &s: v)
        cout << s << endl;
}

void test() {
    int n;
    while(cout << "Enter n: ", cin >> n) {
        vector<string> v1;

        for(int i = 0; i < n; ++i) {
            string s;
            cin >> s;
            v1.push_back(s);
        }

        cout << "output v1: " << endl;
        output(v1); 
        cout << endl;
    }
}

int main() {
    cout << "测试: 使用cin多组输入字符串" << endl;
    test();
}

运行结果截图

4.3.cpp

#include <iostream>
#include <string>
#include <vector>
#include <limits>

using namespace std;

void output(const vector<string> &v) {
    for(auto &s: v)
        cout << s << endl;
}

void test() {
    int n;
    while(cout << "Enter n: ", cin >> n) {
        cin.ignore(numeric_limits<streamsize>::max(), '\n');

        vector<string> v2;

        for(int i = 0; i < n; ++i) {
            string s;
            getline(cin, s);
            v2.push_back(s);
        }
        cout << "output v2: " << endl;
        output(v2); 
        cout << endl;
    }
}

int main() {
    cout << "测试: 使用函数getline()多组输入字符串" << endl;
    test();
}

运行结果截图

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

4.实验5：

grm.hpp

#ifndef GRM_HPP
#define GRM_HPP

template <typename T>
class GameResourceManager {
private:
    T resource;

public:
    // 带参数的构造函数，初始化当前资源数量
    GameResourceManager(T initialResource) : resource(initialResource) {}

    // 获取当前的资源数量
    T get() const {
        return resource;
    }

    // 更新当前的资源数量（增加、减少）
    void update(T change) {
        resource += change;
        if (resource < 0) {
            resource = 0;
        }
    }
};

#endif

test.cpp

#include "grm.hpp"
#include <iostream>

using std::cout;
using std::endl;

void test1() {
    GameResourceManager<float> HP_manager(99.99);
    cout << "当前生命值: " << HP_manager.get() << endl;
    HP_manager.update(9.99);
    cout << "增加9.99生命值后, 当前生命值: " << HP_manager.get() << endl;
    HP_manager.update(-999.99);
    cout << "减少999.99生命值后, 当前生命值: " << HP_manager.get() << endl;
}

void test2() {
    GameResourceManager<int> Gold_manager(100);
    cout << "当前金币数量: " << Gold_manager.get() << endl;
    Gold_manager.update(50);
    cout << "增加50个金币后, 当前金币数量: " << Gold_manager.get() << endl;
    Gold_manager.update(-99);
    cout << "减少99个金币后, 当前金币数量: " << Gold_manager.get() << endl;
}


int main() {
    cout << "测试1: 用float类型对类模板GameResourceManager实例化" << endl;
    test1();
    cout << endl;

    cout << "测试2: 用int类型对类模板GameResourceManager实例化" << endl;
    test2();
}

运行结果截图

5.实验6：

info.hpp

#ifndef INFO_HPP
#define INFO_HPP
#include<iostream>
#include <string>

class Info {
private:
    std::string nickname;
    std::string contact;
    std::string city;
    int n;

public:
    // 带参数的构造函数，用于初始化预约信息
    Info(const std::string& _nickname, const std::string& _contact, const std::string& _city, int _n)
        : nickname(_nickname), contact(_contact), city(_city), n(_n) {}

    // 显示信息（昵称、联系方式、所在城市、预定参加人数）
    void display() const {
        std::cout << "昵称: " << nickname << std::endl;
        std::cout << "联系方式: " << contact << std::endl;
        std::cout << "所在城市: " << city << std::endl;
        std::cout << "预定参加人数: " << n << std::endl;
    }

    // 获取预定参加人数
    int getN() const {
        return n;
    }
};

#endif

6.cpp

#include "info.hpp"
#include <iostream>
#include <vector>
#include <string>
#include <limits>

int main() {
    // 定义一个const常量capacity用于存放livehouse最多能容纳的听众人数
    const int capacity = 100;

    // 定义一个vector<Info>类对象audience_lst，用于存放线上预约登记的所有听众信息
    std::vector<Info> audience_lst;

    // 当前已预约的人数
    int currentCapacity = 0;

    std::string nickname, contact, city;
    int n;

    std::cout << "请输入预约信息（昵称 联系方式 所在城市 预定参加人数，以空格分隔，输入Ctrl+Z或达到场地容量时停止录入）：" << std::endl;

    while (true) {
        if (!(std::cin >> nickname >> contact >> city >> n)) {
            // 检测到Ctrl+Z，结束输入
            if (std::cin.eof()) {
                break;
            }
            // 输入错误，清除错误状态并忽略当前行剩余字符
            std::cin.clear();
            std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
            continue;
        }

        if (currentCapacity + n > capacity) {
            std::cout << "预定参加人数超过livehouse场地剩余容量，请输入q退出预定，或输入u更新预定信息：";
            std::string choice;
            std::cin >> choice;

            if (choice == "q") {
                break;
            }
            else if (choice == "u") {
                std::cout << "请重新输入预约信息（昵称 联系方式 所在城市 预定参加人数，以空格分隔）：";
                continue;
            }
            else {
                std::cout << "无效选择，请重新输入。" << std::endl;
                continue;
            }
        }

        Info newInfo(nickname, contact, city, n);
        audience_lst.push_back(newInfo);
        currentCapacity += n;

        if (currentCapacity >= capacity) {
            std::cout << "已达到场地最大容纳人数，停止预约。" << std::endl;
            break;
        }
    }

    // 打印输出预约参加livehouse的听众信息
    std::cout << "预约参加livehouse的听众信息如下：" << std::endl;
    for (const auto& info : audience_lst) {
        info.display();
    }

    return 0;
}

运行结果截图

6.实验7：

account.h

#pragma once
#include"date.h"
#include"accumulator.h"
#include<string>
using namespace std;
class Account {
private:
    string id;
    double balance;
    static double total;
protected:
    Account(const Date& date, const string& id);
    void record(const Date& date, double amount, const string& desc);
    void error(const string& msg) const;
public:const string& getId() { return id; }
      double getBalance()const { return balance; }
      static double getTotal() { return total; }
      void show()const;
};
class SavingsAccount :public Account {
private:
    Accumulator acc;
    double rate;
public:
    SavingsAccount(const Date& date, const string& id, double rate);
    double getRate() const { return  rate; }
    void deposit(const Date& date, double amount, const string& desc);
    void withdraw(const Date& date, double amount, const string& desc);
    void settle(const Date& date);
};
class CreditAccount :public Account {
private:
    Accumulator acc;
    double credit;
    double rate;
    double fee;
    double getDebt()const {
        double balance = getBalance();
        return(balance < 0 ? balance : 0);
    }
public:CreditAccount(const Date& date, const string& id, double credit, double rate, double fee);
      double getCredit()const { return credit; }
      double getRate()const { return rate; }
      double getFee() const { return fee; }
      double getAvailableCredit()const {
          if (getBalance() < 0)return credit + getBalance();
          else return credit;
      }
      void deposit(const Date& date, double amount, const string& desc);
      void withdraw(const Date& date, double amount, const string& desc);
      void settle(const Date& date);
      void show()const;
};

accumulator.h

#pragma once
#include "date.h"
class Accumulator {
private:
    Date lastDate;
    double value;
    double sum;
public:
    Accumulator(const Date& date, double value) :lastDate(date), value(value), sum{ 0 } {}
    double getSum(const Date& date) const {
        return sum + value * date.distance(lastDate);
    }
    void change(const Date& date, double value) {
        sum = getSum(date);
        lastDate = date;
        this->value = value;
    }
    void reset(const Date& date, double value) {
        lastDate = date;
        this->value;
        sum = 0;
    }
};

date.h

#pragma once
class Date {
private:
    int year;
    int month;
    int day;
    int totalDays;
public:
    Date(int year, int month, int day);
    int getYear()const { return year; }
    int getMonth()const { return month; }
    int getDay()const { return day; }
    int getMaxDay()const;
    bool isLeapYear()const {
        return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
    }
    void show() const;
    int distance(const Date& date)const {
        return totalDays - date.totalDays;
    }
};

account.cpp

#include "account.h"
#include <cmath>
#include<iostream>
using namespace std;
double Account::total = 0;
Account::Account(const Date& date, const string& id) :id(id), balance(0) {
    date.show();
    cout << "\t#" << id << "created" << endl;
}
void Account::record(const Date& date, double amount, const string& desc) {
    amount = floor(amount * 100 + 0.5) / 100;
    balance += amount;
    total += amount;
    date.show();
    cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
}
void Account::show()const { cout << id << "\tBalance:" << balance; }
void Account::error(const string& msg)const {
    cout << "Error(#" << id << "):" << msg << endl;
}
SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :Account(date, id), rate(rate), acc(date, 0) {}
void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
    record(date, amount, desc);
    acc.change(date, getBalance());
}
void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
    if (amount > getBalance()) {
        error("not enough money");
    }
    else {
        record(date, -amount, desc);
        acc.change(date, getBalance());
    }
}
void SavingsAccount::settle(const Date& date) {
    double interest = acc.getSum(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1));
    if (interest != 0)record(date, interest, "interest");
    acc.reset(date, getBalance());
}
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) {}
void CreditAccount::deposit(const Date& date, double amount, const string& desc) {
    record(date, amount, desc);
    acc.change(date, getDebt());
}
void CreditAccount::withdraw(const Date& date, double amount, const string& desc) {
    if (amount - getBalance() > credit) {
        error("not enouogh credit");
    }
    else {
        record(date, -amount, desc);
        acc.change(date, getDebt());
    }
}
void CreditAccount::settle(const Date& date) {
    double interest = acc.getSum(date) * rate;
    if (interest != 0) record(date, interest, "interest");
    if (date.getMonth() == 1)record(date, -fee, "annual fee");
    acc.reset(date, getDebt());
}
void CreditAccount::show()const {
    Account::show();
    cout << "\tAvailable credit:" << getAvailableCredit();
}

date.cpp

#pragma once
#include"date.h"
#include"accumulator.h"
#include<string>
using namespace std;
class Account {
private:
    string id;
    double balance;
    static double total;
protected:
    Account(const Date& date, const string& id);
    void record(const Date& date, double amount, const string& desc);
    void error(const string& msg) const;
public:const string& getId() { return id; }
      double getBalance()const { return balance; }
      static double getTotal() { return total; }
      void show()const;
};
class SavingsAccount :public Account {
private:
    Accumulator acc;
    double rate;
public:
    SavingsAccount(const Date& date, const string& id, double rate);
    double getRate() const { return  rate; }
    void deposit(const Date& date, double amount, const string& desc);
    void withdraw(const Date& date, double amount, const string& desc);
    void settle(const Date& date);
};
class CreditAccount :public Account {
private:
    Accumulator acc;
    double credit;
    double rate;
    double fee;
    double getDebt()const {
        double balance = getBalance();
        return(balance < 0 ? balance : 0);
    }
public:CreditAccount(const Date& date, const string& id, double credit, double rate, double fee);
      double getCredit()const { return credit; }
      double getRate()const { return rate; }
      double getFee() const { return fee; }
      double getAvailableCredit()const {
          if (getBalance() < 0)return credit + getBalance();
          else return credit;
      }
      void deposit(const Date& date, double amount, const string& desc);
      void withdraw(const Date& date, double amount, const string& desc);
      void settle(const Date& date);
      void show()const;
};

7.10.cpp

#include "account.h"
#include<iostream>
using namespace std;
int main() {
    Date date(2008, 11, 1);
    SavingsAccount sa1(date, "S3755217", 0.015);
    SavingsAccount sa2(date, "02342342", 0.015);
    CreditAccount ca(date, "C5392394", 10000, 0.0005, 50);
    sa1.deposit(Date(2008, 11, 5), 5000, "Salary");
    ca.withdraw(Date(2008, 11, 15), 2000, "buy a cell");
    sa2.deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
    ca.settle(Date(2008, 12, 1));
    ca.deposit(Date(2008, 12, 1), 2016, "repay the credit");
    sa1.deposit(Date(2008, 12, 5), 5500, "salary");
    sa1.settle(Date(2009, 1, 1));
    sa2.settle(Date(2009, 1, 1));
    ca.settle(Date(2009, 1, 1));
    cout << endl;
    sa1.show(); cout << endl;
    sa2.show(); cout << endl;
    ca.show(); cout << endl;
    cout << "Total: " << Account::getTotal() << endl;
    return 0;

}

运行结果截图