实验2

任务1：
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();

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 }

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 }

运行结果：

问题1：
t.h中，普通函数 func 作为类X的友元，在类的内部声明了友元关系。在类外部，去掉
line36，重新编译，是否能正确运行。如果能，回答说明可以去掉line36。如果不能，以截图
形式给出编译报错信息，分析可能的原因。

答：不能

截图：

问题2：
t.h中，line9-12给出了各种构造函数、析构函数。总结各种构造函数的功能，以及它们与析
构函数的调用时机。

答：1.普通构造函数T(int x = 0, int y = 0)：

功能：用于初始化类 T 的对象，参数 x 和 y 可以用来设置对象的成员变量 m1 和 m2。如果不传入参数，则默认值为0。

调用时机：当创建T类的新对象时调用。

2.复制构造函数T(const T &t)：

功能：用于创建一个新对象，作为已有对象t的副本，它复制对象t的所有成员变量。

调用时机：当使用已存在的对象初始化另一个对象时。

3.移动构造函数T(T &&t)：

功能：用于移动构造对象。适用于临时对象

调用时机：：在使用 std::move 或当临时对象被用来初始化新对象

4.析构函数 ~T()：

功能：用于清理资源，当对象的生命周期结束时调用，释放动态分配的内存

调用时机：当对象超出作用域

问题3：
t.cpp中，line13-15，调整到t.h，重新编译，程序能否正确编译运行。

答：不能

任务2：
Complex.h

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

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 
 7 // 构造实数
 8 Complex::Complex(double r) : real(r), imag(0) {}
 9 
10 // 构造复数
11 Complex::Complex(double r, double i) : real(r), imag(i) {}
12 
13 Complex::Complex(const Complex &c) : real(c.real), imag(c.imag) {}
14 
15 
16 double Complex::get_real() const {
17     return real;
18 }
19 
20 double Complex::get_imag() const {
21     return imag;
22 }
23 
24 void Complex::add(const Complex &c) {
25     real += c.real;
26     imag += c.imag;
27 }
28 
29 Complex add(const Complex &c1, const Complex &c2) {
30     return Complex(c1.real + c2.real, c1.imag + c2.imag);
31 }
32 
33 bool is_equal(const Complex &c1, const Complex &c2) {
34     return (c1.real == c2.real) && (c1.imag == c2.imag);
35 }
36 
37 bool is_not_equal(const Complex &c1, const Complex &c2) {
38     return !is_equal(c1, c2);
39 }
40 
41 void output(const Complex &c) {
42     std::cout << c.real << (c.imag >= 0 ? " + " : " - ") << std::abs(c.imag) << "i";
43 }
44 
45 double abs(const Complex &c) {
46     return std::sqrt(c.real * c.real + c.imag * c.imag);
47 }

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 = "; output(c1); cout << endl;
21     cout << "c2 = "; output(c2); cout << endl;
22     cout << "c3 = "; output(c3); cout << endl;
23     cout << "c4 = "; output(c4); 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 = "; output(c1); 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 = "; output(c4); cout << endl;
37 }
38 
39 int main() {
40     test();
41     return 0;
42 }

运行结果截图：

任务3：
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 }

运行结果：

任务4：
Fraction.h

 1 #ifndef FRACTION_H
 2 #define FRACTION_H
 3 
 4 #include <string>
 5 
 6 class Fraction {
 7 public:
 8     static const std::string doc;
 9 
10     Fraction(int up, int down = 1); 
11     Fraction(const Fraction& other); 
12 
13     int get_up() const;         
14     int get_down() const;       
15     Fraction negative() const;  
16 
17     friend void output(const Fraction& f);    
18     friend Fraction add(const Fraction& f1, const Fraction& f2); // 加法
19     friend Fraction sub(const Fraction& f1, const Fraction& f2); // 减法
20     friend Fraction mul(const Fraction& f1, const Fraction& f2); // 乘法
21     friend Fraction div(const Fraction& f1, const Fraction& f2); // 除法
22 
23 private:
24     int up;    
25     int down;  
26     void simplify(); 
27 };
28 
29 #endif

Fraction.cpp

 1 #include "Fraction.h"
 2 #include <stdexcept>
 3 #include <iostream>
 4 
 5 const std::string Fraction::doc = "Fraction类 v 0.01版";
 6 
 7 int gcd(int a, int b) {
 8     while (b != 0) {
 9         int temp = b;
10         b = a % b;
11         a = temp;
12     }
13     return a;
14 }
15 
16 Fraction::Fraction(int up, int down) : up(up), down(down) {
17     if (down == 0) throw std::invalid_argument("分母不能为0");
18     simplify();
19 }
20 
21 Fraction::Fraction(const Fraction& other) : up(other.up), down(other.down) {}
22 
23 int Fraction::get_up() const { 
24     return up; 
25 }
26 
27 int Fraction::get_down() const { 
28     return down; 
29 }
30 
31 Fraction Fraction::negative() const {
32     return Fraction(-up, down);
33 }
34 
35 void Fraction::simplify() {
36     int gcdValue = gcd(up, down);
37     up /= gcdValue;
38     down /= gcdValue;
39     if (down < 0) { 
40         up = -up;
41         down = -down;
42     }
43 }
44 
45 void output(const Fraction& f) {
46     if (f.get_down() == 1) {
47         std::cout << f.get_up();  
48     } else {
49         std::cout << f.get_up() << "/" << f.get_down();  
50     }
51 }
52 
53 // 加法
54 Fraction add(const Fraction& f1, const Fraction& f2) {
55     return Fraction(f1.up * f2.down + f2.up * f1.down, f1.down * f2.down);
56 }
57 
58 // 减法
59 Fraction sub(const Fraction& f1, const Fraction& f2) {
60     return Fraction(f1.up * f2.down - f2.up * f1.down, f1.down * f2.down);
61 }
62 
63 // 乘法
64 Fraction mul(const Fraction& f1, const Fraction& f2) {
65     return Fraction(f1.up * f2.up, f1.down * f2.down);
66 }
67 
68 // 除法
69 Fraction div(const Fraction& f1, const Fraction& f2) {
70     if (f2.up == 0) throw std::invalid_argument("分子不能为0");
71     return Fraction(f1.up * f2.down, f1.down * f2.up);
72 }

task4.cpp

 1 #include "Fraction.h"
 2 #include <iostream>
 3 #include <stdexcept>
 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     Fraction f1(5); 
12     Fraction f2(3, -4), f3(-18, 12);
13     Fraction f4(f3);
14     
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() = " << f5.get_down() << endl; 
23     cout << "f1 + f2 = "; output(add(f1, f2)); cout << endl; 
24     cout << "f1 - f2 = "; output(sub(f1, f2)); cout << endl; 
25     cout << "f1 * f2 = "; output(mul(f1, f2)); cout << endl; 
26     cout << "f1 / f2 = "; output(div(f1, f2)); cout << endl; 
27     cout << "f4 + f5 = "; output(add(f4, f5)); cout << endl; 
28 }
29 
30 void test2() {
31     try {
32         Fraction f6(42, 55), f7(0, 3); 
33         cout << "f6 = "; output(f6); cout << endl; 
34         cout << "f7 = "; output(f7); cout << endl; 
35         cout << "f6 / f7 = "; output(div(f6, f7)); cout << endl; 
36     } catch (const std::invalid_argument& e) {
37         cout  << e.what() << endl;  
38     }
39 }
40 
41 int main() {
42     cout << "测试1: Fraction类基础功能测试\n"; 
43     test1();
44     cout << "\n测试2: 分母为0测试: \n"; 
45     test2();
46     return 0;
47 }

运行结果截图：

任务5：
account.h

 1 #ifndef __ACCOUNT_H__
 2 #define __ACCOUNT_H__
 3 
 4 class SavingsAccount {
 5 private:
 6     int id;
 7     double balance;
 8     double rate;
 9     int lastDate; 
10     double accumulation;
11     static double total;
12     void record(int date, double amount);
13     double accumulate(int date) const {
14         return accumulation + balance * (date - lastDate);
15     }
16 
17 public:
18     SavingsAccount(int date, int id, double rate);
19     int getId() const { return id; }
20     double getBalance() const { return balance; }
21     double getRate() const { return rate; } 
22     static double getTotal() { return total; }
23     void deposit(int date, double amount);
24     void withdraw(int date, double amount);
25     void settle(int date);
26     void show() const; 
27 };
28 
29 #endif // __ACCOUNT_H__

account.cpp

 1 //account.cpp
 2 #include "account.h"
 3 #include <cmath>
 4 #include <iostream>
 5 using namespace std;
 6 
 7 double SavingsAccount::total = 0;
 8 
 9 SavingsAccount::SavingsAccount(int date, int id, double rate)
10     : id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
11     cout << date << "\t# " << id << " is created" << endl;
12 }
13 
14 void SavingsAccount::record(int date, double amount) {
15     accumulation = accumulate(date);
16     lastDate = date;
17     amount = floor(amount * 100 + 0.5) / 100; // Rounding to two decimal places
18     balance += amount;
19     total += amount;
20     cout << date << "\t# " << id << "\t" << amount << "\t" << balance << endl;
21 }
22 
23 void SavingsAccount::deposit(int date, double amount) {
24     record(date, amount); // Corrected the semicolon
25 }
26 
27 void SavingsAccount::withdraw(int date, double amount) {
28     if (amount > getBalance())
29         cout << "Error: not enough money" << endl;
30     else
31         record(date, -amount);
32 }
33 
34 void SavingsAccount::settle(int date) {
35     double interest = accumulate(date) * rate / 365;
36     if (interest != 0)
37         record(date, interest);
38     accumulation = 0;
39 }
40 
41 void SavingsAccount::show() const { // Corrected the spelling
42     cout << "#" << id << "\tBalance: " << balance << endl;
43 }

5_11.cpp

 1 //5_11.cpp
 2 #include"account.h"
 3 #include<iostream>
 4 using namespace std;
 5 int main(){
 6     SavingsAccount sa0(1,21325302,0.015);
 7     SavingsAccount sa1(1,58320212,0.015);
 8     sa0.deposit(5,5000);
 9     sa1.deposit(25,10000);
10     sa0.deposit(45,5500);
11     sa0.withdraw(6,4000);
12     sa0.settle(90);
13     sa1.settle(90);
14     sa0.show();cout<<endl;
15     sa1.show();cout<<endl;
16     cout<<"Total:"<<SavingsAccount::getTotal()<<endl;
17     return 0;
18 }

运行结果截图：

posted @ 2024-10-28 09:20 芮欣婷阅读(16) 评论(0) 收藏举报

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