实验任务1：

实验代码：

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();
View Code

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 }
View Code

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 }
View Code

实验截图1：

问题1：不行。

实验截图2：

去掉line36后，相当于只在类T中对func()进行了友元函数声明，而未在类T外进行其函数本身的声明。

问题2：1.普通构造函数：在对象被创建时利用特定的值构造对象，将对象初始化为一个特定的状态。在对象被创建时被自动调用；

2.复制构造函数：使用一个已经存在的对象，去初始化同类的一个新对象。

3.移动构造函数：直接挪用已有右值对象的成员资源，配合move函数使用完成新对象移动构造。

4.析构函数：用来完成对象被删除前的一些清理工作。在对象的生存期即将结束的时刻被自动调用；

5.默认构造函数：调用时无须提供参数的普通构造函数。

问题3：无法正确编译运行。

 

实验任务2：

实验代码：

complex.h:

 1 #ifndef COMPLEX_H
 2 #define COMPLEX_H
 3 
 4 #include <iostream>
 5 #include <string>
 6 #include <cmath>
 7 
 8 class Complex {
 9 public:
10     static const std::string doc;
11     Complex();
12     Complex(double r);
13     Complex(double r, double i);
14     Complex(const Complex& other);
15     
16     double get_real() const;
17     double get_imag() const;
18     void add(const Complex& other);
19     
20     friend Complex add(const Complex& c1, const Complex& c2);
21     friend bool is_equal(const Complex& c1,const Complex& c2);
22     friend bool is_not_equal(const Complex& c1,const Complex& c2);
23     
24     friend double abs(const Complex& c);
25     friend void output(const Complex& c);
26 private:
27     double real;
28     double imag;
29 };
30 
31 #endif
View Code

complex.cpp:

 1 #include "Complex.h"
 2 
 3 const std::string Complex::doc = "a simplified Complex class";
 4 
 5 Complex::Complex() : real{0}, imag{0} {}
 6 Complex::Complex(double r) : real{r}, imag{0} {}
 7 Complex::Complex(double r, double i) : real{r}, imag{i} {}
 8 Complex::Complex(const Complex& other) : real{other.real}, imag{other.imag} {} 
 9 
10 double Complex::get_real() const {
11     return real;
12 }
13 
14 double Complex::get_imag() const {
15     return imag;
16 }
17 
18 void Complex::add(const Complex& other) {
19     real += other.real;
20     imag += other.imag;
21 }
22 
23 Complex add(const Complex& c1, const Complex& c2) {
24     return Complex(c1.real + c2.real, c1.imag + c2.imag);
25 }
26 bool is_equal(const Complex& c1,const Complex& c2) {
27     return (c1.real == c2.real) && (c1.imag == c2.imag);
28 }
29 
30 bool is_not_equal(const Complex& c1,const Complex& c2) {
31     return !is_equal(c1, c2);
32 }
33 
34 void output(const Complex& c) {
35     if(c.imag < 0) 
36     std::cout << c.real << " - " << abs(c.imag) << "i";
37     else
38     std::cout << c.real << " + " << c.imag << "i";
39 }
40 
41 double abs(const Complex& c) {
42     return std::sqrt(c.real * c.real + c.imag * c.imag);
43 }
View Code

main.cpp:

 1 #include "Complex.h"
 2 
 3 using std::cout;
 4 using std::endl;
 5 using std::boolalpha;
 6 
 7 void test() {
 8     cout << "类成员测试: " << endl;
 9     cout << Complex::doc << endl;
10 
11     cout << endl;
12 
13     cout << "Complex对象测试: " << endl;
14     Complex c1;
15     Complex c2(3, -4);
16     const Complex c3(3.5);
17     Complex c4(c3);
18 
19     cout << "c1 = "; output(c1); cout << endl;
20     cout << "c2 = "; output(c2); cout << endl;
21     cout << "c3 = "; output(c3); cout << endl;
22     cout << "c4 = "; output(c4); cout << endl;
23     cout << "c4.real = " << c4.get_real() << ", c4.imag = " << c4.get_imag() << endl;
24 
25     cout << endl;
26 
27     cout << "复数运算测试: " << endl;
28     cout << "abs(c2) = " << abs(c2) << endl;
29     c1.add(c2);
30     cout << "c1 += c2, c1 = "; output(c1); cout << endl;
31     cout << boolalpha;
32     cout << "c1 == c2 : " << is_equal(c1, c2) << endl;
33     cout << "c1 != c3 : " << is_not_equal(c1, c3) << endl;
34     c4 = add(c2, c3);
35     cout << "c4 = c2 + c3, c4 = "; output(c4); cout << endl;
36 }
37 
38 int main() {
39     test();
40 }
View Code

实验截图：

 

实验任务3：

实验代码：

 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 }
View Code

实验截图：

 

实验任务4：

实验代码：

Fraction.h:

 1 #ifndef FRACTION H
 2 #define FRACTION H
 3 
 4 #include <iostream>
 5 #include <string>
 6 #include <cmath>
 7 
 8 class Fraction {
 9 public:
10     static const std::string doc;
11     Fraction(int u);
12     Fraction(int u, int d);
13     Fraction(const Fraction& other);
14     
15     int get_up() const;
16     int get_down() const;
17     Fraction negative() const;
18     void reduce();
19     
20     friend void output(const Fraction& f);
21     friend Fraction add(const Fraction& f1, const Fraction& f2);
22     friend Fraction sub(const Fraction& f1, const Fraction& f2);
23     friend Fraction mul(const Fraction& f1, const Fraction& f2);
24     friend Fraction div(const Fraction& f1, const Fraction& f2);
25 private:
26     int up;
27     int down;
28 };
29 
30 #endif
View Code

Fraction.cpp:

 1 #include "Fraction.h"
 2 
 3 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.";
 4 
 5 Fraction::Fraction(int u): up{u}, down{1} {}
 6 Fraction::Fraction(int u, int d): up{u}, down{d} {
 7     if(down == 0) {
 8     std::cout << "分母不能为0"; 
 9 } 
10     reduce();
11 }
12 Fraction::Fraction(const Fraction& other): up{other.up}, down{other.down} {}
13 
14 int gcd(int a, int b) {  
15     int r;
16     while (b > 0){
17         r = a % b;
18         a = b;
19         b = r;
20     }
21     return a;
22 }
23 
24 int Fraction::get_up() const {
25     return up;
26 }
27 
28 int Fraction::get_down() const {
29     return down;
30 } 
31 
32 void Fraction::reduce() {
33     int x = gcd(abs(up), abs(down));
34     up /= x;
35     down /= x; 
36 }
37 
38 Fraction Fraction::negative() const {
39     return Fraction(-up, down);
40 }
41 
42 void output(const Fraction& f) {
43     if(f.up * f.down < 0) {
44         if (f.up % f.down == 0)
45         std::cout << "-" << abs(f.up) / abs(f.down);
46         else
47         std::cout << "-" << abs(f.up) << "/" << abs(f.down);
48     }
49     else {
50         if(f.up % f.down == 0)
51         std::cout << abs(f.up) / abs(f.down);
52         else
53         std::cout << abs(f.up) << "/" << abs(f.down);
54     }
55 }
56 
57 Fraction add(const Fraction& f1, const Fraction& f2) {
58     return Fraction(f1.up * f2.down + f2.up * f1.down, f1.down * f2.down);
59 }
60 
61 Fraction sub(const Fraction& f1, const Fraction& f2) {
62     return Fraction(f1.up * f2.down - f2.up * f1.down, f1.down * f2.down);
63 }
64 
65 Fraction mul(const Fraction& f1, const Fraction& f2) {
66     return Fraction(f1.up * f2.up, f1.down * f2.down);
67 }
68 
69 Fraction div(const Fraction& f1, const Fraction& f2) {
70     return Fraction(f1.up * f2.down, f1.down * f2.up);
71 }
View Code

main.cpp:

 1 #include "Fraction.h"
 2 #include <iostream>
 3  
 4 using std::cout;
 5 using std::endl;
 6 
 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     Fraction f5(f4.negative());
21     cout << "f5 = "; output(f5); cout << endl;
22     cout << "f5.get_up() = " << f5.get_up() << ", f5.get_down() = " << 
23 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 }
View Code

实验截图：

 

实验任务5：

实验代码：

account.h:

 1 #ifndef __ACCOUNT_H__
 2 #define __ACCOUNT_H__
 3 class SavingsAccount {
 4 private:
 5     int id;
 6     double balance;
 7     double rate;
 8     int lastDate;
 9     double accumulation;
10     static double total;
11     void record(int date, double amount);
12     double accumulate(int date) const{
13         return accumulation + balance*(date - lastDate);
14     }
15 public:
16     SavingsAccount(int date, int id, double rate);
17     int getId() const {return id;}
18     double getBalance() const {return balance;}
19     double getRate() const {return rate;}
20     static double getTotal() {return total;}
21     void deposit(int date, double amount);
22     void withdraw(int date, double amount);
23     
24     void settle(int date);
25     void show() const;
26 };
27 #endif
View Code

account.cpp:

 1 #include "account.h"
 2 #include <cmath>
 3 #include <iostream>
 4 using namespace std;
 5 
 6 double SavingsAccount::total = 0;
 7 
 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     accumulation = accumulate(date);
13     lastDate = date;
14     amount = floor(amount * 100 + 0.5) / 100;
15     balance += amount;
16     total += amount;
17     cout << date << "\t#" << id << "\t" << amount << "\t" << balance << endl;
18 }
19 void SavingsAccount::deposit(int date, double amount) {
20     record(date, amount);
21 }
22 void SavingsAccount::withdraw(int date, double amount) {
23     if(amount > getBalance())
24         cout << "Error: not enough money" << endl;
25     else
26         record(date, -amount);
27 }
28 void SavingsAccount::settle(int date) {
29     double interest = accumulate(date) * rate / 365;
30     if(interest != 0) record(date, interest);
31     accumulation = 0; 
32 }
33 void SavingsAccount::show() const {
34     cout << "#" << id << "\tBalance: " << balance;
35 }
View Code

main.cpp:

 1 #include "account.h"
 2 #include <iostream>
 3 using namespace std;
 4 int main() {
 5     SavingsAccount sa0(1, 21325302, 0.015);
 6     SavingsAccount sa1(1, 58320212, 0.015);
 7     
 8     sa0.deposit(5, 5000);
 9     sa1.deposit(25, 10000);
10     sa0.deposit(45, 5500);
11     sa1.withdraw(60, 4000);
12     
13     sa0.settle(90);
14     sa1.settle(90);
15     
16     sa0.show(); cout << endl;
17     sa1.show(); cout << endl;
18     cout << "Total: " << SavingsAccount::getTotal() << endl;
19     return 0;
20 }
View Code

实验截图：

挺好的：）