程序设计实验2
任务1
task1.cpp
1 #include "t.h" 2 #include <iostream> 3 4 using std::cout; 5 using std::endl; 6 7 void test(); 8 9 int main() { 10 test(); 11 cout << "\nmain: \n"; 12 cout << "T objects'current count: " << T::get_cnt() << endl; 13 } 14 15 void test() { 16 cout << "test class T: \n"; 17 cout << "T info: " << T::doc << endl; 18 cout << "T objects'max count: " << T::max_cnt << endl; 19 cout << "T objects'current count: " << T::get_cnt() << endl << endl; 20 21 22 T t1; 23 cout << "t1 = "; t1.display(); cout << endl; 24 25 T t2(3, 4); 26 cout << "t2 = "; t2.display(); cout << endl; 27 28 T t3(t2); 29 t3.adjust(2); 30 cout << "t3 = "; t3.display(); cout << endl; 31 32 T t4(std::move(t2)); 33 cout << "t3 = "; t4.display(); cout << endl; 34 35 cout << "T objects'current count: " << T::get_cnt() << endl; 36 37 func(); 38 }
t.cpp
1 // 类T: 实现 2 // 普通函数实现 3 4 #include "t.h" 5 #include <iostream> 6 #include <string> 7 8 using std::cout; 9 using std::endl; 10 using std::string; 11 12 // static成员数据类外初始化 13 const std::string T::doc{"a simple class sample"}; 14 const int T::max_cnt = 999; 15 int T::cnt = 0; 16 17 18 // 对象方法 19 T::T(int x, int y): m1{x}, m2{y} { 20 ++cnt; 21 cout << "T constructor called.\n"; 22 } 23 24 T::T(const T &t): m1{t.m1}, m2{t.m2} { 25 ++cnt; 26 cout << "T copy constructor called.\n"; 27 } 28 29 T::T(T &&t): m1{t.m1}, m2{t.m2} { 30 ++cnt; 31 cout << "T move constructor called.\n"; 32 } 33 34 T::~T() { 35 --cnt; 36 cout << "T destructor called.\n"; 37 } 38 39 void T::adjust(int ratio) { 40 m1 *= ratio; 41 m2 *= ratio; 42 } 43 44 void T::display() const { 45 cout << "(" << m1 << ", " << m2 << ")" ; 46 } 47 48 // 类方法 49 int T::get_cnt() { 50 return cnt; 51 } 52 53 // 友元 54 void func() { 55 T t5(42); 56 t5.m2 = 2049; 57 cout << "t5 = "; t5.display(); cout << endl; 58 }
t.h
1 #pragma once 2 3 #include <string> 4 5 // 类T: 声明 6 class T { 7 // 对象属性、方法 8 public: 9 T(int x = 0, int y = 0); // 普通构造函数 10 T(const T &t); // 复制构造函数 11 T(T &&t); // 移动构造函数 12 ~T(); // 析构函数 13 14 void adjust(int ratio); // 按系数成倍调整数据 15 void display() const; // 以(m1, m2)形式显示T类对象信息 16 17 private: 18 int m1, m2; 19 20 // 类属性、方法 21 public: 22 static int get_cnt(); // 显示当前T类对象总数 23 24 public: 25 static const std::string doc; // 类T的描述信息 26 static const int max_cnt; // 类T对象上限 27 28 private: 29 static int cnt; // 当前T类对象数目 30 31 // 类T友元函数声明 32 friend void func(); 33 }; 34 35 // 普通函数声明 36 void func();
代码运行截图：
问题一：可以去掉line36，代码正常运行。
问题二：普通构造函数初始化变量，复制构造函数是对同类对象的引用，移动构造函数是对参数右值的引用，编译周期结束时，自动调用析构函数。
问题三：不能运行，
任务二
task2.cpp
1 #include "Complex.h" 2 #include <iostream> 3 4 using std::cout; 5 using std::endl; 6 using std::boolalpha; 7 8 void test() { 9 cout << "类成员测试: " << endl; 10 cout << Complex::doc << endl; 11 12 cout << endl; 13 14 cout << "Complex对象测试: " << endl; 15 Complex c1; 16 Complex c2(3, -4); 17 const Complex c3(3.5); 18 Complex c4(c3); 19 20 cout << "c1 = "; c1.output(); cout << endl; 21 cout << "c2 = "; c2.output(); cout << endl; 22 cout << "c3 = "; c3.output(); cout << endl; 23 cout << "c4 = "; c4.output(); cout << endl; 24 cout << "c4.real = " << c4.get_real() << ", c4.imag = " << c4.get_imag() << endl; 25 26 cout << endl; 27 28 cout << "复数运算测试: " << endl; 29 cout << "abs(c2) = " << abs(c2) << endl; 30 c1.add(c2); 31 cout << "c1 += c2, c1 = "; c1.output(); cout << endl; 32 cout << boolalpha; 33 cout << "c1 == c2 : " << is_equal(c1, c2) << endl; 34 cout << "c1 != c3 : " << is_not_equal(c1, c3) << endl; 35 c4 = add(c2, c3); 36 cout << "c4 = c2 + c3, c4 = "; c4.output(); cout << endl; 37 38 } 39 40 int main() { 41 test(); 42 43 }
Complex.h
1 #pragma once 2 #ifndef COMPLEX_H 3 #define COMPLEX_H 4 5 #include <string> 6 #include<iostream> 7 #include<cmath> 8 // 类Complex: 声明 9 class Complex { 10 public: 11 Complex(); 12 Complex(double r); 13 Complex(double r, double i); 14 Complex(const Complex& c); 15 double get_real()const; 16 double get_imag()const; 17 void add(const Complex& c); 18 19 //~Complex(); // 析构函数 20 //void output(const Complex& c); 21 void output()const; 22 //void Complex add(const Complex& c); 23 static const std::string doc; 24 friend Complex add(const Complex& c1, const Complex& c2); 25 friend bool is_equal(const Complex& c1, const Complex& c2); 26 friend bool is_not_equal(const Complex& c1, const Complex& c2); 27 friend double abs(const Complex& c); 28 //friend Complex output(const Complex& c); 29 friend std::ostream& operator<<(std::ostream& os, const Complex& c); 30 31 private: 32 double real; 33 double imag; 34 35 }; 36 37 #endif // COMPLEX_H
Complex.cpp
1 #include "Complex.h" 2 // 普通函数实现 3 #include <iostream> 4 #include <string> 5 using std::cout; 6 using std::endl; 7 using std::string; 8 9 // static成员数据类外初始化 10 const std::string Complex::doc= " a simplified complex class" ; 11 12 13 // 对象方法 14 Complex::Complex() :real(0), imag( 0 ) {} 15 Complex::Complex(double r) :real(r), imag( 0 ) {} 16 Complex::Complex(double r, double i) :real( r ), imag(i) {} 17 Complex::Complex(const Complex& c) : real(c.real), imag(c.imag) {} 18 19 20 // 类方法 21 double Complex::get_real()const{ 22 return real; 23 } 24 double Complex::get_imag() const{ 25 return imag; 26 } 27 void Complex::add(const Complex& c) { 28 real += c.real; 29 imag += c.imag; 30 }//将复数加到自身 31 std::ostream& operator<<(std::ostream& os, const Complex& c) { 32 os << c.real << (c.imag >= 0 ? "+" : "") << c.imag << "i"; 33 return os; 34 }// 输出流重载 35 Complex add(const Complex& c1, const Complex& c2) { 36 return Complex(c1.real + c2.real, c1.imag + c2.imag); 37 }//加法友元 38 bool is_equal(const Complex& c1, const Complex& c2) { 39 return (c1.real == c2.real) && (c1.imag == c2.imag); 40 }//判等友元 41 bool is_not_equal(const Complex& c1, const Complex& c2) { 42 return !is_equal(c1, c2); 43 }//判不等友元 44 double abs(const Complex& c) { 45 return std::sqrt(c.real * c.real + c.imag * c.imag); 46 }//取模友元 47 void Complex::output() const { 48 if(imag>=0) 49 std::cout<< real << " + " << imag << "i" << std::endl; 50 else 51 std::cout << real << " - " << imag*(-1) << "i" << std::endl; 52 }//输出
代码运行截图：
任务三
task3.cpp
1 #include <iostream> 2 #include <complex> 3 4 using std::cout; 5 using std::endl; 6 using std::boolalpha; 7 using std::complex; 8 9 void test() { 10 cout << "标准库模板类comple测试: " << endl; 11 complex<double> c1; 12 complex<double> c2(3, -4); 13 const complex<double> c3(3.5); 14 complex<double> c4(c3); 15 16 cout << "c1 = " << c1 << endl; 17 cout << "c2 = " << c2 << endl; 18 cout << "c3 = " << c3 << endl; 19 cout << "c4 = " << c4 << endl; 20 cout << "c4.real = " << c4.real() << ", c4.imag = " << c4.imag() << endl; 21 cout << endl; 22 23 cout << "复数运算测试: " << endl; 24 cout << "abs(c2) = " << abs(c2) << endl; 25 c1 += c2; 26 cout << "c1 += c2, c1 = " << c1 << endl; 27 cout << boolalpha; 28 cout << "c1 == c2 : " << (c1 == c2) << endl; 29 cout << "c1 != c3 : " << (c1 != c3) << endl; 30 c4 = c2 + c3; 31 cout << "c4 = c2 + c3, c4 = " << c4 << endl; 32 } 33 34 int main() { 35 test(); 36 }
代码运行截图：
运用接口有：real，imag，operator+-*/=
标准库函数complex输出更加简洁，没有任务二中代码如此冗赘。
任务四
task4.cpp
1 #include "Fraction.h" 2 #include <iostream> 3 #include <numeric> 4 5 using std::cout; 6 using std::endl; 7 8 void test1() { 9 cout << "Fraction类测试: " << endl; 10 cout << Fraction::doc << endl << endl; 11 12 Fraction f1(5); 13 Fraction f2(3, -4), f3(-18, 12); 14 Fraction f4(f3); 15 cout << "f1 = "; output(f1); cout << endl; 16 cout << "f2 = "; output(f2); cout << endl; 17 cout << "f3 = "; output(f3); cout << endl; 18 cout << "f4 = "; output(f4); cout << endl; 19 20 21 Fraction f5(f4.negative()); 22 cout << "f5 = "; output(f5); cout << endl; 23 cout << "f5.get_up() = " << f5.get_up() << ", f5.get_down() = " << f5.get_down() << endl; 24 25 cout << "f1 + f2 = "; output(add(f1, f2)); cout << endl; 26 cout << "f1 - f2 = "; output(sub(f1, f2)); cout << endl; 27 cout << "f1 * f2 = "; output(mul(f1, f2)); cout << endl; 28 cout << "f1 / f2 = "; output(div(f1, f2)); cout << endl; 29 cout << "f4 + f5 = "; output(add(f4, f5)); cout << endl; 30 } 31 32 void test2() { 33 Fraction f6(42, 55), f7(0, 3); 34 cout << "f6 = "; output(f6); cout << endl; 35 cout << "f7 = "; output(f7); cout << endl; 36 cout << "f6 / f7 = "; output(div(f6, f7)); cout << endl; 37 } 38 39 int main() { 40 cout << "测试1: Fraction类基础功能测试\n"; 41 test1(); 42 43 cout << "\n测试2: 分母为0测试: \n"; 44 test2(); 45 return 0; 46 }
Fraction.h
1 #pragma once 2 3 #ifndef FRACTION_H 4 #define FRACTION_H 5 6 #include<iostream> 7 #include<string> 8 #include <numeric> 9 class Fraction 10 { 11 public: 12 //Fraction(); 13 //Fraction(int u); 14 Fraction(int u=0, int d=1); 15 Fraction(const Fraction& f); 16 17 //接口 18 int get_up()const; 19 int get_down()const; 20 Fraction negative()const; 21 22 static const std::string doc; 23 24 //友元 25 friend Fraction add(const Fraction& f1, const Fraction& f2); 26 friend Fraction sub(const Fraction& f1, const Fraction& f2); 27 friend Fraction mul(const Fraction& f1, const Fraction& f2); 28 friend Fraction div(const Fraction& f1, const Fraction& f2); 29 friend void output(const Fraction& f); 30 31 private: 32 int up; 33 int down; 34 35 void simplify(); 36 }; 37 38 #endif//FRACTION_H
Fraction.cpp
1 #include "Fraction.h" 2 #include<iostream> 3 #include<string> 4 #include <numeric> 5 6 using std::cout; 7 using std::endl; 8 using std::string; 9 10 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."; 11 12 //Fraction::Fraction() :up(0), down(1) {} 13 //Fraction::Fraction(int u):up(u),down(1){} 14 //Fraction::Fraction(int u,int d):up(u),down(d){} 15 16 Fraction::Fraction(int u, int d) : up(u), down(d) { 17 //if (d == 0) { 18 // //throw std::invalid_argument("分母不能为零"); 19 // //printf("分母不能为0"); 20 //} 21 simplify(); 22 } 23 24 Fraction::Fraction(const Fraction&f) :up(f.up), down(f.down) {} 25 26 int gcd(int a, int b) { 27 while (b != 0) { 28 int temp = b; 29 b = a % b; 30 a = temp; 31 } 32 return abs(a); // 返回绝对值 33 } 34 35 void Fraction::simplify() { 36 if (down < 0) { // 保证分母为正 37 up = -up; 38 down = -down; 39 } 40 int divisor = gcd(abs(up), abs(down)); 41 up /= divisor; 42 down /= divisor; 43 } 44 45 46 int Fraction::get_up()const { 47 return up; 48 } 49 int Fraction::get_down()const { 50 return down; 51 } 52 Fraction Fraction::negative()const { 53 return Fraction(-up, down); 54 } 55 56 //友元 57 void output(const Fraction& f) 58 { 59 if (f.get_up() == 0 && f.get_down() == 0) 60 printf("分母不能为0\n"); 61 else if(f.get_up() == 0 && f.get_down() != 0) 62 std::cout <<"0" << std::endl; 63 else 64 std::cout << f.get_up() << "/" << f.get_down() << std::endl; 65 } 66 Fraction add(const Fraction& f1, const Fraction& f2) 67 { 68 return Fraction(f1.get_up()*f2.get_down()+f2.get_up()*f1.get_down(),f1.get_down()*f2.get_down()); 69 } 70 Fraction sub(const Fraction& f1, const Fraction& f2) 71 { 72 return Fraction(f1.get_up() * f2.get_down() - f2.get_up() * f1.get_down(), f1.get_down() * f2.get_down()); 73 } 74 Fraction mul(const Fraction& f1, const Fraction& f2) 75 { 76 return Fraction(f1.get_up() * f2.get_up() , f1.get_down() * f2.get_down()); 77 } 78 Fraction div(const Fraction& f1, const Fraction& f2) { 79 if (f2.get_up() == 0) { 80 //throw std::invalid_argument("除数不能为零"); 81 printf("分母不能为0\n"); 82 Fraction f(0, 0); 83 return f; 84 } 85 return Fraction(f1.get_up() * f2.get_down(), f1.get_down() * f2.get_up()); 86 }
代码运行截图：
任务五
task5.cpp
1 #include<iostream> 2 #include"account.h" 3 using namespace std; 4 int main() 5 { 6 //建立几个账户 7 SavingsAccount sa0(1, 21325302, 0.015); 8 SavingsAccount sa1(1, 58320212, 0.015); 9 //几笔账目 10 sa0.deposit(5, 5000); 11 sa1.deposit(25, 10000); 12 sa0.deposit(45, 5500); 13 sa1.withdraw(60, 4000); 14 //开户后第90天到了银行的计息日，结算所有账户的年息 15 sa0.settle(90); 16 sa1.settle(90); 17 //输出各个账户信息 18 sa0.show(); cout << endl; 19 sa1.show(); cout << endl; 20 cout << "Total:" << SavingsAccount::getTotal() << endl; 21 return 0; 22 }
account.h
1 #pragma once 2 #ifndef ACCOUNT_H 3 #define ACCOUNT_H 4 5 6 class SavingsAccount 7 {//储蓄账户类 8 private: 9 int id;//账号 10 double balance;//余额 11 double rate;//存款的年利率 12 int lastDate;//上次变更余额的时期 13 double accumulation;//余额按日累加之和 14 static double total;//所有账户的总金额 15 //记录一笔账，date为日期，amount为金额，desc为说明 16 void record(int date, double amount); 17 //获得到指定日期为止的存款金额按日累积值 18 double accumulate(int date)const { 19 return accumulation + balance * (date - lastDate); 20 } 21 public: 22 //构造函数 23 SavingsAccount(int date, int id, double rate); 24 int getId()const { return id; } 25 double getBalance()const { return balance; } 26 double getRate()const { return rate; } 27 static double getTotal(){ return total; } 28 void deposit(int date, double amount);//存入现金 29 void withdraw(int date, double amount);//取出现金 30 //结算利息，每年一月一日调用一次该函数 31 void settle(int date); 32 //显示账户信息 33 void show()const; 34 }; 35 36 #endif // ! ACCOUNT_H
account.cpp
1 #include "account.h" 2 #include<cmath> 3 #include<iostream> 4 using namespace std; 5 6 double SavingsAccount::total = 0; 7 //SavingsAccount类相关成员函数的实现 8 SavingsAccount::SavingsAccount(int date, int id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0) { 9 cout << date << "\t#" << id << "is created" << endl; 10 } 11 void SavingsAccount::record(int date, double amount) 12 { 13 accumulation = accumulate(date); 14 lastDate = date; 15 amount = floor(amount * 100 + 0.5) / 100;//保留小数点后两位 16 balance += amount; 17 total += amount; 18 cout << date << "\t#" << id << "\t" << amount << "\t" << balance << endl; 19 } 20 void SavingsAccount::deposit(int date, double amount) { 21 record(date, amount); 22 } 23 void SavingsAccount::withdraw(int date, double amount) 24 { 25 if (amount > getBalance()) 26 cout << "Error:not enough money" << endl; 27 else 28 record(date, amount); 29 } 30 void SavingsAccount::settle(int date) { 31 double interest = accumulate(date) * rate / 365;//计算年息 32 if (interest != 0) 33 record(date, interest); 34 accumulation = 0; 35 } 36 void SavingsAccount::show()const { 37 cout << "#" << id << "\tBalance:" << balance; 38 }
代码运行截图：
代码简洁，目标明确，精确封装各类要求，没有冗赘项目。
