实验二

task 1

main.cpp

#include "t.h"
#include <iostream>
 
using std::cout;
using std::endl;
 
void test();
 
int main() {
    test();
    cout << "\nmain: \n";
    cout << "T objects'current count: " << T::get_cnt() << endl;
}
 
void test() {
    cout << "test class T: \n";
    cout << "T info: " << T::doc << endl;
    cout << "T objects'max count: " << T::max_cnt << endl;
    cout << "T objects'current count: " << T::get_cnt() << endl << endl;
 
 
    T t1;
    cout << "t1 = "; t1.display(); cout << endl;
 
    T t2(3, 4);
    cout << "t2 = "; t2.display(); cout << endl;
 
    T t3(t2);
    t3.adjust(2);
    cout << "t3 = "; t3.display(); cout << endl;
 
    T t4(std::move(t2));
    cout << "t3 = "; t4.display(); cout << endl;
 
    cout << "T objects'current count: " << T::get_cnt() << endl;
 
    func();
}

　　t.h

#pragma once

#include <string>

// 类T: 声明
class T {
// 对象属性、方法
public:
    T(int x = 0, int y = 0);   // 普通构造函数
    T(const T &t);  // 复制构造函数
    T(T &&t);       // 移动构造函数
    ~T();           // 析构函数

    void adjust(int ratio);      // 按系数成倍调整数据
    void display() const;           // 以(m1, m2)形式显示T类对象信息

private:
    int m1, m2;

// 类属性、方法
public:
    static int get_cnt();          // 显示当前T类对象总数

public:
    static const std::string doc;       // 类T的描述信息
    static const int max_cnt;           // 类T对象上限

private:
    static int cnt;         // 当前T类对象数目

// 类T友元函数声明
    friend void func();
};

// 普通函数声明
void func();

t.cpp

// 类T: 实现
// 普通函数实现

#include "t.h"
#include <iostream>
#include <string>

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

// static成员数据类外初始化
const std::string T::doc{"a simple class sample"};
const int T::max_cnt = 999;
int T::cnt = 0;


// 对象方法
T::T(int x, int y): m1{x}, m2{y} { 
    ++cnt; 
    cout << "T constructor called.\n";
} 

T::T(const T &t): m1{t.m1}, m2{t.m2} {
    ++cnt;
    cout << "T copy constructor called.\n";
}

T::T(T &&t): m1{t.m1}, m2{t.m2} {
    ++cnt;
    cout << "T move constructor called.\n";
}    

T::~T() {
    --cnt;
    cout << "T destructor called.\n";
}           

void T::adjust(int ratio) {
    m1 *= ratio;
    m2 *= ratio;
}    

void T::display() const {
    cout << "(" << m1 << ", " << m2 << ")" ;
}     

// 类方法
int T::get_cnt() {
   return cnt;
}

// 友元
void func() {
    T t5(42);
    t5.m2 = 2049;
    cout << "t5 = "; t5.display(); cout << endl;
}

运行结果：

问题一：能

问题二：普通构造函数可以初始化两个成员变量或者传递参数来完成初始化；

              复制构造函数可以创建一个新对象，并将参数对象的成员变量值复制到新创建的对象中；

             移动构造函数在不进行复制的情况下，将一个临时对象或即将销毁的对象的资源移动到新创建的对象中；

            析构函数用于在对象的生命周期结束时进行清理工作；

   问题三：不能

task 2

Complex.h

#ifndef COMPLEX_H
#define COMPLEX_H

#include <string>

class Complex {
public:
    static const std::string doc; 
    
    Complex(); 
    Complex(double real); // 构造复数，实部为real，虚部为0
    Complex(double real, double imag); // 构造复数，实部为real，虚部为imag
    Complex(const Complex& other); 

    // 获取实部和虚部
    double get_real() const;
    double get_imag() const;

    // 加法操作
    void add(const Complex& other);
    friend Complex add(const Complex& c1, const Complex& c2); 

    // 判断复数是否相等
    friend bool is_equal(const Complex& c1, const Complex& c2); 
    friend bool is_not_equal(const Complex& c1, const Complex& c2); 

    // 输出复数
    friend std::ostream& operator<<(std::ostream& os, const Complex& c); 
    friend void output(const Complex& c); 

    // 取模运算
    friend double abs(const Complex& c);

private:
    double real;
    double imag;
};

#endif 

Complex.cpp

#include "Complex.h"
#include <iostream>
#include <cmath>

const std::string Complex::doc = "a simplified complex class";

Complex::Complex() : real(0), imag(0) {}

Complex::Complex(double real) : real(real), imag(0) {}

Complex::Complex(double real, double imag) : real(real), imag(imag) {}

Complex::Complex(const Complex& other) : real(other.real), imag(other.imag) {}

double Complex::get_real() const {
    return real;
}

double Complex::get_imag() const {
    return imag;
}

void Complex::add(const Complex& other) {
    real += other.real;
    imag += other.imag;
}

Complex add(const Complex& c1, const Complex& c2) {
    return Complex(c1.real + c2.real, c1.imag + c2.imag);
}

bool is_equal(const Complex& c1, const Complex& c2) {
    return (c1.real == c2.real) && (c1.imag == c2.imag);
}

bool is_not_equal(const Complex& c1, const Complex& c2) {
    return !is_equal(c1, c2);
}

std::ostream& operator<<(std::ostream& os, const Complex& c) {
    os << c.real << " + " << c.imag << "i";
    return os;
}

void output(const Complex& c) {
    std::cout << c;
}

double abs(const Complex& c) {
    return std::sqrt(c.real * c.real + c.imag * c.imag);
}

main

#include <iostream>
#include "Complex.h"

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

void test() {
    cout << "类成员测试: " << endl;
    cout << Complex::doc << endl;
    cout << endl;

    cout << "Complex对象测试: " << endl;
    Complex c1;
    Complex c2(3, -4);
    const Complex c3(3.5);
    Complex c4(c3);
    cout << "c1 = "; output(c1); cout << endl;
    cout << "c2 = "; output(c2); cout << endl;
    cout << "c3 = "; output(c3); cout << endl;
    cout << "c4 = "; output(c4); cout << endl;
    cout << "c4.real = " << c4.get_real() << ", c4.imag = " << c4.get_imag() << endl;
    cout << endl;

    cout << "复数运算测试: " << endl;
    cout << "abs(c2) = " << abs(c2) << endl;
    c1.add(c2);
    cout << "c1 += c2, c1 = "; output(c1); cout << endl;
    cout << boolalpha;
    cout << "c1 == c2 : " << is_equal(c1, c2) << endl;
    cout << "c1 != c3 : " << is_not_equal(c1, c3) << endl;
    c4 = add(c2, c3);
    cout << "c4 = c2 + c3, c4 = "; output(c4); cout << endl;
}

int main() {
    test();
    return 0;
}

运行代码：

task 3

#include <iostream>
#include <complex>

using std::cout;
using std::endl;
using std::boolalpha;
using std::complex;

void test() {
    cout << "标准库模板类comple测试: " << endl;
    complex<double> c1;
    complex<double> c2(3, -4);
    const complex<double> c3(3.5);
    complex<double> c4(c3);

    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;
    cout << "c3 = " << c3 << endl;
    cout << "c4 = " << c4 << endl;
    cout << "c4.real = " << c4.real() << ", c4.imag = " << c4.imag() << endl;
    cout << endl;

    cout << "复数运算测试: " << endl;
    cout << "abs(c2) = " << abs(c2) << endl;
    c1 += c2;
    cout << "c1 += c2, c1 = " << c1 << endl;
    cout << boolalpha;
    cout << "c1 == c2 : " << (c1 == c2) << endl;
    cout << "c1 != c3 : " << (c1 != c3) << endl;
    c4 = c2 + c3;
    cout << "c4 = c2 + c3, c4 = " << c4 << endl;
}

int main() {
    test();
}

 

task 4

Fraction.h

#pragma once
#include <iostream>

class Fraction {

  public:
     static const std::string doc; // 描述信息

     Fraction(int numerator = 0, int denominator = 1); // 构造函数
     Fraction(const Fraction &f); // 拷贝构造函数

     int get_up() const; // 返回分子
     int get_down() const; // 返回分母
     Fraction negative() const; // 求负

     friend void output(const Fraction &f); //输出
     friend Fraction add(const Fraction &f1, const Fraction &f2);
     friend Fraction sub(const Fraction &f1, const Fraction &f2);
     friend Fraction mul(const Fraction &f1, const Fraction &f2);
     friend Fraction div(const Fraction &f1, const Fraction &f2);
    
  private:
     int up;   // 分子
     int down; // 分母

     void simplify(); // 简化分数


 };

Fraction.cpp

#include "Fraction.h"
#include<iostream>

const std::string Fraction::doc = "Fraction类 v 0.01版. 目前仅支持分数对象的构造、输出、加/减/乘/除运算。";


int gcd1(int a,int b)
 {
    return b==0?a:gcd1(b,a%b);
 }

Fraction::Fraction(int numerator, int denominator) : up(numerator), down(denominator) {
    if (down == 0) {
        std::cout<<"分母不能为0"<<std::endl;
     }
     simplify();
 }

Fraction::Fraction(const Fraction &f) : up(f.up), down(f.down) {}

void Fraction::simplify() {
     int gcd = gcd1(up, down);
     up /= gcd;
     down /= gcd;
     if (down < 0) { // 保持负号在分子上
         up = -up;
         down = -down;
     }
 }

int Fraction::get_up() const {
     return up;
 }

int Fraction::get_down() const {
     return down;
 }

Fraction Fraction::negative() const {
     return Fraction(-up, down);
 }

void output(const Fraction &f){
     if(f.down!=0){

     if(f.down==1)
        std::cout<<f.up<<std::endl;
     else
       std::cout<<f.up<<"/"<<f.down<<std::endl;
   }
 }

Fraction add(const Fraction &f1, const Fraction &f2) {
     return Fraction(f1.up * f2.down + f2.up * f1.down, f1.down * f2.down);
 }

Fraction sub(const Fraction &f1, const Fraction &f2) {
     return Fraction(f1.up * f2.down - f2.up * f1.down, f1.down * f2.down);
 }

Fraction mul(const Fraction &f1, const Fraction &f2) {
     return Fraction(f1.up * f2.up, f1.down * f2.down);
 }

Fraction div(const Fraction &f1, const Fraction &f2) {
     if (f2.up == 0) {
         std::cout<<"分母不能为0"<<std::endl;
     }
     else
         return Fraction(f1.up * f2.down, f1.down * f2.up);
 }

main

#include "Fraction.h"
#include <iostream>

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

void test1() {
  cout << "Fraction类测试: " << endl;
  cout << Fraction::doc << endl << endl;

  Fraction f1(5);
  Fraction f2(3, -4), f3(-18, 12);
  Fraction f4(f3);
  cout << "f1 = "; output(f1); cout << endl;
  cout << "f2 = "; output(f2); cout << endl;
  cout << "f3 = "; output(f3); cout << endl;
  cout << "f4 = "; output(f4); cout << endl;

  Fraction f5(f4.negative());
  cout << "f5 = "; output(f5); cout << endl;
  cout << "f5.get_up() = " << f5.get_up() << ", f5.get_down() = " << f5.get_down() << endl;

  cout << "f1 + f2 = "; output(add(f1, f2)); cout << endl;
  cout << "f1 - f2 = "; output(sub(f1, f2)); cout << endl;
  cout << "f1 * f2 = "; output(mul(f1, f2)); cout << endl;
  cout << "f1 / f2 = "; output(div(f1, f2)); cout << endl;
  cout << "f4 + f5 = "; output(add(f4, f5)); cout << endl;
 }

void test2() {
  Fraction f6(42, 55), f7(0, 3);
  cout << "f6 = "; output(f6); cout << endl;
  cout << "f7 = "; output(f7); cout << endl;
  cout << "f6 / f7 = "; output(div(f6, f7)); cout << endl;
}

int main() {
  cout << "测试1: Fraction类基础功能测试\n";
  test1();

  cout << "\n测试2: 分母为0测试: \n";
  test2();
 }

运行截图

 

task 5

account.h

#pragma once

#ifndef ACCOUNT_H__
#define ACCOUNT_H__
class SavingAccount{
    private:
        int id;
        double balance;
        double rate;
        int lastDate;
        double accumulation;
        static double total;
        
        void record(int date,double amount);
        double accumulate(int date) const{
            return accumulation+balance*(date-lastDate);
        }
        
    public:
        SavingAccount(int date,int id,double rate);
        int getId() const{return id;}
        double getBalance() const{return balance;}
        double getRate() const{return rate;}
        static double getTotal() {return total;}
        void deposit(int date,double amount);
        void withdraw(int date,double amount);
        void settle(int date);
        void show() const;
};
#endif

account.app

#include "account.h"
#include <cmath>
#include <iostream>
using namespace std;

double SavingAccount::total=0;

SavingAccount::SavingAccount(int date,int id,double rate)
    :id(id),balance(0),rate(rate),lastDate(date),accumulation(0){
        cout<<date<<"\t#"<<id<<"is created"<<endl;
    }
void SavingAccount::record(int date,double amount){
    accumulation=accumulate(date);
    lastDate=date;
    amount=floor(amount*100+0.5)/100;
    balance+=amount;
    total+=amount;
    cout<<date<<"\t#"<<id<<"\t"<<amount<<"\t"<<balance<<endl;
}
void SavingAccount::deposit(int date,double amount){
    record(date,amount);
}
void SavingAccount::withdraw(int date,double amount){
    if(amount>getBalance()){
        cout<<"Error:not enough money"<<endl;
    }
    else{
        record(date,-amount);
    }
}
void SavingAccount::settle(int date){
    double interest=accumulate(date)*rate/365;
    if(interest!=0)
       record(date,interest);
    accumulation=0;
}
void SavingAccount::show() const{
    cout<<"#"<<id<<"\tBalance:"<<balance;
}

main.cpp

#include "account.h"
#include <iostream>
using namespace std;

int main(){
    SavingAccount sa0(1,21325302,0.015);
    SavingAccount sa1(1,58320212,0.015);
    
    sa0.deposit(5,5000);
    sa1.deposit(25,10000);
    sa0.deposit(45,5500);
    sa1.withdraw(60,4000);
    sa0.settle(90);
    sa1.settle(90);
    sa0.show();cout<<endl;
    sa1.show();cout<<endl;
    cout<<"Total:"<<SavingAccount::getTotal()<<endl;
    return 0;
}

截图：

 问题：我认为合理，不需要改进。