实验2 类和对象_基础编程1

任务1：

#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();

// 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;
}

#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();
}

问题1：不能。对于友元函数没有作声明

问题2：普通构造函数：初始化对象；复制构造函数：用一个已有的对象来初始化一个新的对象；移动构造函数：资源从一个对象“移动”到另一个对象中，而不是进行复制；析构函数：释放在构造函数或在对象生命期内获取的资源

问题3：不能

 

 

任务2：

#ifndef COMPLEX_H
#define COMPLEX_H

#include <string>

class Complex {
public:
    static const std::string doc;
    Complex();
    Complex(double realVal);
    Complex(double realVal, double imagVal);
    Complex(const Complex& other);
    double get_real() const;
    double get_imag() const;
    void add(const Complex& other);
    friend Complex add(const Complex& c1, const Complex& c2);
    friend bool is_equal(const Complex& c1, const Complex& c2);
    friend bool is_not_equal(const Complex& c1, const Complex& c2);
    friend void output(const Complex& c);
    friend double abs(const Complex& c);
private:
    double real;
    double imag;
};

#endif

#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 realVal) : real(realVal), imag(0) {}

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

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) {
    Complex result;
    result.real = c1.real + c2.real;
    result.imag = c1.imag + c2.imag;
    return result;
}

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));
}

void output(const Complex& c) {
    std::cout << c.real;
    if (c.imag > 0) {
        std::cout << "+";
    }
    std::cout << c.imag << "i" << std::endl;
}

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

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

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();
}

 

 

 

 

任务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();
}

 

 

 

 

 

任务4：

#ifndef FRACTION_H
#define FRACTION_H

#include <string>

class Fraction {
public:
    static const std::string doc;
    Fraction();
    Fraction(int upVal);
    Fraction(int upVal, int downVal);
    Fraction(const Fraction& other);
    int get_up() const;
    int get_down() const;
    Fraction negative() const;
    friend void output(const Fraction& f);
    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;
    int down;
    int gcd(int a, int b) const;
    void simplify();
};

#endif

#include "Fraction.h"
#include <iostream>
const std::string Fraction::doc = "Fraction类v 0.01版.\n目前仅支持分数对象的构造、输出、加/减/乘/除运算.";

Fraction::Fraction() : up(0), down(1) {}

Fraction::Fraction(int upVal) : up(upVal), down(1) {}

Fraction::Fraction(int upVal, int downVal) {
    if (downVal == 0) {
        std::cerr << "分母不能为0" << std::endl;
        return;
    }
    up = upVal;
    down = downVal;
    simplify();
}

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

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

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

Fraction Fraction::negative() const {
    Fraction result;
    result.up = -up;
    result.down = down;
    return result;
}

int Fraction::gcd(int a, int b) const {
    return b == 0? a : gcd(b, a % b);
}

void Fraction::simplify() {
    if (down < 0) {
        up = -up;
        down = -down;
    }
    int divisor = gcd(std::abs(up), down);
    up = up / divisor;
    down = down / divisor;
}

void output(const Fraction& f) {
    if (f.down == 1) {
        std::cout << f.up;
    } else {
        if (f.up < 0) {
            std::cout << '-' << -f.up << '/' << f.down;
        } else {
            std::cout << f.up << '/' << f.down;
        }
    }
}

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

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

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

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

#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();
}

 

 

 

 

 

任务5：

 #include<iostream>
 
 
 class SavingsAccount{
     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:
         SavingsAccount(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 rate,double amount);
         void withdraw(int rate,double amount);
         void settle(int date);
         void show() const;
 };

#include "account.h"
 #include<cmath>
 #include<iostream>
 using std::cout;
 using std::endl;
  double SavingsAccount::total=0;
  SavingsAccount::SavingsAccount(int date,int id,double rate)
     :id(id),balance{0},rate{rate},lastDate{date},accumulation{0}{
     cout<<date<<"\t#"<<id<<"is created"<<endl;
 } 
 void SavingsAccount::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 SavingsAccount::deposit(int date,double amount){
     record(date,amount);
 }  
 void SavingsAccount::withdraw(int date,double amount){
     if(amount>getBalance()){
         cout<<"Erroe:not enough money"<<endl;
     }
     else{
         record(date,-amount);
     }
 }
 
 void SavingsAccount::settle(int date){
     double interest=accumulate(date)*rate/365;
     if(interest!=0){
         record(date,interest);
     }
     accumulation=0;
 }  
 void SavingsAccount::show() const{
     cout<<"#"<<id<<"\tBalance:"<<balance;
 }

#include "account.h"
 #include<iostream>
 
 using namespace std;  
 int main(){
     SavingsAccount sa0(1,21325302,0.015);
     SavingsAccount 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:"<<SavingsAccount::getTotal()<<endl; 
     return 0;
 }