实验2 C++-编程知识

实验2 C++

news/2024/10/23 21:26:55/文章来源:https://www.cnblogs.com/tt3n/p/18494354

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 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 };

t.cpp

// 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.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：能正常运行，因为func()已经在类内部声明为友元函数，无需在类外再次声明。

问题2：

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；主函数中声明T t2(3,4) 时调用。

复制构造函数：使用一个已经存在的对象（由复制构造函数的参数指定），去初始化同类的一个新对象；主函数中声明T t3(t2) 时调用。

移动构造函数：通过移动右值引用对象来安全地构造新对象，并且避免冗余复制对象的代价；主函数中T t4(std::move(t2)) 时调用。

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

问题3：不能正确运行。

任务2：

Complex.h

 1 #include <stdlib.h> 
 2 #include <string>
 3 #include <math.h>
 4 
 5 using namespace std;
 6 
 7 class Complex{
 8     public:
 9         Complex(double r,double i);
10         Complex(double r);
11         Complex();
12         Complex(const Complex&c);
13     private:
14         double real;
15         double imag;
16         
17     public:
18         static const string doc;
19     public:
20         double get_real() const;
21         double get_imag() const;                    
22         void add(const Complex &c); 
23     friend Complex add(const Complex &c1,const Complex &c2);
24     friend bool is_equal(const Complex &c1,const Complex &c2);
25     friend bool is_not_equal(const Complex &c1,const Complex &c2);
26     friend void output(Complex c);
27     friend double abs(Complex c);    
28 };

Complex.cpp

 1 #include "y.h"
 2 
 3 using namespace std;
 4 
 5 const string Complex::doc{"a simplified Complex calss"};
 6 
 7 Complex::Complex(double r,double i){
 8     real=r;
 9     imag=i;
10 }
11 
12 Complex::Complex(double r) {real=r;imag=0;}
13 
14 Complex::Complex() {real=0;imag=0;}
15 
16 Complex::Complex(const Complex&c){
17     real=c.real;
18     imag=c.imag;
19 }
20 
21 double Complex::get_real() const {
22     return real; 
23 }
24 
25 double Complex::get_imag() const {
26     return imag;
27 }
28 
29 void Complex::add(const Complex &c){
30     real+=c.real;
31     imag+=c.imag;
32 }
33 
34 Complex add(const Complex &c1,const Complex &c2){
35     Complex sum;
36     sum.real+=c1.real+c2.real;
37     sum.imag+=c1.imag+c2.imag;
38     return sum;
39 }
40 
41 bool is_equal(const Complex &c1,const Complex &c2){
42     bool flag=false;
43     if(c1.real==c2.real && c1.imag==c2.imag)
44         flag=true;
45     return flag;
46 }
47 
48 bool is_not_equal(const Complex &c1,const Complex &c2){
49     bool flag=true;
50     if(c1.real==c2.real && c1.imag==c2.imag)
51         flag=false;
52     return flag;
53 }
54 
55 void output(Complex c){
56     cout<<c.real;
57     if(c.imag<0)
58         cout<<" - "<<-c.imag<<'i';
59     else
60         cout<<" + "<<c.imag<<'i';
61 }
62 
63 double abs(Complex c){
64     double ans=0;
65     double r1,i1;
66     r1=c.real*c.real;
67     i1=c.imag*c.imag;
68     ans=sqrt(r1+i1);
69     return ans;
70 }

task2.cpp

 1 #include "y.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 }

运行结果：

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：

1）1.使用了默认构造函数 Complex() {real=0;imag=0;} 2.使用普通构造函数 Complex(double r) {real=r;imag=0;} 和 Complex(double r,double i){real=r;imag=i;} 3.使用复制构造函数 Complex(const Complex&c){real=c.real;imag=c.imag;} 4.使用判断两个复数类是否相等的函数 5.使用复数类加法函数。

2）1.声明不同：此代码通过 Complex <数据类型> 类名称（输入数据）的方法声明；用real() 和 imag() 代替了 get_real 和 get_imag；省略了输出函数output()；通过(c1==c2)等式子可直接返回bool类型值；

复数类可直接进行加法运算。

2.可以将输出函数写进构造函数中以避免其反复出现，节约空间。

任务4：

Fraction.h

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

Fraction.cpp

  1 #include "Fraction.h"
  2 
  3 using namespace std;
  4 
  5 Fraction::Fraction() {
  6     up=1;
  7     down=1;
  8 }
  9 
 10 Fraction::Fraction(int u) {
 11     up=u;
 12     down=1;
 13 }
 14 
 15 Fraction::Fraction(int u,int d) {
 16     up=u;
 17     down=d;
 18 }
 19 
 20 Fraction::Fraction(const Fraction &f) {
 21     up=f.up;
 22     down=f.down;
 23 }
 24 
 25 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"};
 26 
 27 int Fraction::get_up() const { 
 28 
 29     if(!up && down)
 30         return 0;    
 31     else if(down){
 32         int up1=up,down1=down;
 33         int r=up1%down1;
 34         while(r){
 35             up1=down1;
 36             down1=r;
 37             r=up1%down1;
 38         }//最大公约数；
 39         r=down1;
 40         up1=up/r;
 41         return up1;
 42     }
 43 }
 44 int Fraction::get_down() const {
 45     if(down){
 46         int up1=up,down1=down;
 47         int r=up1%down1;
 48         while(r){
 49             up1=down1;
 50             down1=r;
 51             r=up1%down1;
 52         }//最大公约数；
 53         r=down1;
 54         down1=down/r;
 55         return down1;
 56     }
 57     else{
 58         cout<<"分母不能为0";
 59         return 0; 
 60     }
 61 }
 62 Fraction Fraction::negative() {
 63     Fraction f0;
 64     f0.up=-up;
 65     f0.down=down;
 66     return f0;
 67 }
 68 
 69 void output(Fraction f){
 70     int up1=f.get_up(),down1=f.get_down();
 71     if(!up1 && down1)
 72         cout<<0;
 73     else if(down1){
 74     int flag=1;
 75     if(up1*down1<0) 
 76         flag=-1;
 77         
 78     up1=abs(up1);
 79     down1=abs(down1);
 80     cout<<flag*up1<<'/'<<down1;
 81     }
 82     
 83 }
 84 
 85 Fraction add(Fraction f1,Fraction f2){
 86     Fraction f0;
 87     int up1=f1.up,down1=f1.down,up2=f2.up,down2=f2.down;
 88     
 89     int flag1=1,flag2=1;
 90     if(up1*down1<0)
 91         flag1=-1;
 92     if(up2*down2<0)
 93         flag2=-1;
 94     
 95     up1=abs(up1);
 96     up2=abs(up2);
 97     down1=abs(down1);
 98     down2=abs(down2);
 99       
100     int down_m;
101     int r=down1%down2;
102     while(r){
103         down1=down2;
104         down2=r;
105         r=down1%down2;
106     }//最大公约数；
107     r=down2;
108     
109     down1=abs(f1.down);
110     down2=abs(f2.down);
111     
112     down_m=down1*down2/r;//最小公倍数
113     up1*=down_m/down1; 
114     up2*=down_m/down2; //约分 
115     
116     f0.up=flag1*up1+flag2*up2;
117     f0.down=down_m;
118     return f0;
119 }
120 
121 Fraction sub(Fraction f1,Fraction f2){
122     Fraction f0=add(f1,f2.negative());
123     return f0;
124 }
125 
126 
127 Fraction mul(Fraction f1,Fraction f2){
128     Fraction f0;
129     f0.up=f1.up*f2.up;
130     f0.down=f1.down*f2.down; 
131     return f0;
132 }
133 
134 Fraction div(Fraction f1,Fraction f2){
135     Fraction f0;
136     f0.up=f1.up*f2.down;
137     f0.down=f1.down*f2.up; 
138     return f0;
139 }

task4.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() = " << f5.get_down() << endl;
23 
24     cout << "f1 + f2 = "; output(add(f1, f2)); cout << endl;
25     cout << "f1 - f2 = "; output(sub(f1, f2)); cout << endl;
26     cout << "f1 * f2 = "; output(mul(f1, f2)); cout << endl;
27     cout << "f1 / f2 = "; output(div(f1, f2)); cout << endl;
28     cout << "f4 + f5 = "; output(add(f4, f5)); cout << endl;
29 }
30 
31 void test2() {
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 }
37 
38 int main() {
39     cout << "测试1: Fraction类基础功能测试\n";
40     test1();
41 
42     cout << "\n测试2: 分母为0测试: \n";
43     test2();
44 }

运行结果：

任务5：

account.h

 1 class SavingAccount{
 2     private:
 3         int id;
 4         double balance;
 5         double rate;
 6         int lastDate;
 7         double accumulation;
 8         static double total;
 9         
10         void record(int,double);
11         double accumulate(int date) const {
12             return accumulation+balance*(date-lastDate);
13         }
14     public:
15         SavingAccount(int,int,double);
16         int get_ID() const {return id;}
17         double getBalance() const {return balance;}
18         double getRate() const {return rate;}
19         static double getTotal() {return total;}
20         void deposit(int,double);
21         void withdraw(int,double);
22         void settle(int);
23         void show() const;
24 };

account.cpp

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

5_11.cpp

 1 #include "account.h"
 2 #include <iostream>
 3 using namespace std;
 4 int main(){
 5     SavingAccount sa0(1,21325302,0.015);
 6     SavingAccount 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     sa0.settle(90);
13     sa1.settle(90);
14     sa0.show();cout<<endl;
15     sa1.show();cout<<endl;
16     cout<<"Total: "<<SavingAccount::getTotal()<<endl;
17     return 0; 
18 }