实验2
任务1：
t.h代码：
#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代码：
// 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; }
task1代码：
#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(); }
运行结果：
问题一：
不能。
原因可能是没有声明函数。
问题二：
普通构造函数实现了对类的初始化，复制构造函数主要用于初始化一个新的对象，使其成为另一个同类型对象的副本，它会将引用的源对象的值复制到新对象中。移动构造函数的作用是提高程序的效率，其通过右值引用创建新对象，它避免了深拷贝，直接转移原始对象的资源到新对象中，从而减少了复制的时间。析构函数作用是在对象生命周期结束时进行资源清理。当前三种构造函数全部结束时析构函数会自动调用多遍。
问题3：
不能正确编译。
任务2：
Complex.h代码：
#ifndef COMPLEX_H #define COMPLEX_H #include<string> using namespace std; class Complex{ private: double real; double imag; public: Complex(); Complex(double x); Complex(double x1,double x2); Complex(const Complex &y); ~Complex(); public: double get_real()const; double get_imag()const; void add(const Complex &y); friend Complex add(const Complex &a,const Complex &b); friend bool is_equal(const Complex &a,const Complex &b); friend bool is_not_equal(const Complex &a,const Complex &b); friend void output(const Complex &x); friend double abs(const Complex &x); static const string doc; }; #endif
Complex.cpp代码：
#include<iostream> #include<string> #include<cmath> #include"Complex.h" using namespace std; const string Complex::doc{"a simplified Complex class"}; Complex::Complex():real(0),imag(0){} Complex::Complex(double x):real(x){} Complex::Complex(double x1,double x2):real(x1),imag(x2){} Complex::Complex(const Complex &y){ real=y.get_real(); imag=y.get_imag(); } Complex::~Complex(){} double Complex::get_real()const{ return real; } double Complex::get_imag()const{ return imag; } void Complex::add(const Complex &y){ real+=y.get_real(); imag+=y.get_imag(); } Complex add(const Complex &a,const Complex &b){ Complex c; c.real=a.get_real()+b.get_real(); c.imag=a.get_imag()+b.get_imag(); return c; } bool is_equal(const Complex &a,const Complex &b){ if(a.get_real()==b.get_real()&&a.get_imag()==b.get_imag()) return true; else return false; } bool is_not_equal(const Complex &a,const Complex &b){ if(a.get_real()==b.get_real()&&a.get_imag()==b.get_imag()) return false; else return true; } void output(const Complex &x){ cout<<x.get_real(); if(x.get_imag()<0) { cout<<" - "; double d; d=(-1.0)*x.get_imag(); cout<<d<<"i"; } else cout<<" + "<<x.get_imag() <<"i"; } double abs(const Complex &x){ double m,n; m=pow(x.get_real(),2)+pow(x.get_imag(),2); n=sqrt(m); return n; }
main.cpp代码：
#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(); }
运行结果：
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(); }
运行结果：
complex库可以大大简化程序，我认为complex就是一个现成的类，使用了之后就省去了我们构造类的过程。
任务4：
Fraction.h代码：
#ifndef FRACTION_H #define FRACTION_H #include<iostream> #include<string> using namespace std; class Fraction{ private: int up; int down; public: Fraction(); Fraction(int val); Fraction(int val1,int val2); Fraction(const Fraction &a); ~Fraction(); public: int get_up()const ; int get_down()const ; Fraction negative(); public: friend void output(const Fraction &a); friend Fraction add( const Fraction &a,const Fraction &b); friend Fraction sub(const Fraction &a,const Fraction &b); friend Fraction mul(const Fraction &a, const Fraction &b); friend Fraction div(const Fraction &a,const Fraction &b); static const string doc; }; #endif
Fraction.cpp代码：
#include<iostream> #include<string> #include<cmath> #include"Fraction.h" using namespace std; const 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(){} Fraction::Fraction(int val):up(val),down(1){} Fraction::Fraction(int val1, int val2):up(val1),down(val2){} Fraction::Fraction(const Fraction &a){up=a.up;down=a.down;} Fraction::~Fraction(){} int Fraction::get_up()const{ return up; } int Fraction::get_down()const{ return down; } Fraction Fraction::negative(){ Fraction c; c.up=-up; c.down=down; int p,q; p=max(c.get_up(),c.get_down()); q=min(c.get_up(),c.get_down()); if(c.get_up()==c.get_down()) { c.up=1; c.down=1; } else if(c.get_down()==0) cout<<"分母不能为0"; else{ while(true) { if(p%q==0) { c.down=c.get_down()/q; c.up=c.get_up()/q; break; } else{ int t=p; p=q; q=t%q; } } } return c; } void output(const Fraction &a) { Fraction c(a); int p,q; p=max(c.get_up(),c.get_down()); q=min(c.get_up(),c.get_down()); if(c.get_up()==c.get_down()) { c.up=1; c.down=1; cout<<"1"; } else if(c.get_up()==0&&c.get_down()!=0) { cout<<"0"; } else if(c.get_down()==0) cout<<"分母不能为0"; else if(c.get_down()==1) cout<<c.get_up(); else{ while(true) { if(p%q==0) { c.down=c.get_down()/q; c.up=c.get_up()/q; break; } else{ int t=p; p=q; q=t%q; } } cout<<c.get_up()<<"/"<<c.get_down(); } } Fraction add(const Fraction &a,const Fraction &b){ Fraction c; c.down=a.get_down()*b.get_down(); c.up=a.get_up()*b.get_down()+b.get_up()*a.get_down(); return c; } Fraction sub(const Fraction &a,const Fraction &b){ Fraction c; c.down=a.get_down()*b.get_down(); c.up=a.get_up()*b.get_down()-b.get_up()*a.get_down(); return c; } Fraction mul(const Fraction &a,const Fraction &b){ Fraction c; c.down=a.get_down()*b.get_down(); c.up=a.get_up()*b.get_up(); return c; } Fraction div(const Fraction &a,const Fraction &b){ Fraction c; c.down=a.get_down()*b.get_up(); c.up=a.get_up()*b.get_down(); return c; }
main1.cpp代码：
#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：
任务5：
account.h:
#ifndef ACCOUNT_H #define ACCOUNT_H #include<iostream> 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);//存入现金 void withdraw(int date,double amount);//取出现金 //结算利息，每年1月1日调用一次下函数 void settle(int date); void show()const; }; #endif
account.cpp:
#include"account.h" #include<iostream> #include<cmath> 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; }
运行截图：
