实验1

#include<iostream>
using std::cout;
using std::endl;

class Point{
public:
    Point(int x0=0,int y0=0);
    Point(const Point& p);
    ~Point()=default;
    
    int get_x() const{return x;}
    int get_y() const{return y;}
    void show() const;
    
private:
    int x,y;
};

Point::Point(int x0,int y0):x{x0},y{y0}
{
    cout<<"constructor called."<<endl;
}
Point::Point(const Point& p):x{p.x}, y{p.y} {
    cout<<"copy constructor called."<<endl;
}
void Point::show() const{
    cout<<"("<<x<<","
             <<y<<")"<<endl;
}

int main(){
    Point p1(4,5);
    p1.show();
    Point p2=p1;
    p2.show();
    Point p3{p2};
    p3.show();
    cout<<p3.get_x()<<endl;
    
}

task2运行结果：

task3：

#include<iostream>
#include<iomanip>

using std::cout;
using std::endl;

class Clock {
public:
    Clock(int h = 0, int m = 0, int s = 0);
    Clock(const Clock& t);
    ~Clock() = default;

    void set_time(int h, int m = 0, int s = 0);
    void show_time() const;

private:
    int hour, minute, second;
};

Clock::Clock(int h, int m, int s) :  hour{ h }, minute{m}, second{ s } 
{
      cout << "constructor called" << endl;
}

Clock::Clock(const Clock & t) : hour{ t.hour }, minute{ t.minute }, second{ t.second } { 
      cout << "copy constructor called" << endl; 
}


void Clock::set_time(int h, int m, int s) { 
    hour = h; minute = m; second = s;
}

void Clock::show_time() const { 
    using std::setw; using std::setfill; 
    
    cout << setfill('0') << setw(2) << hour << ":" 
        << setw(2) << minute << ":" 
        << setw(2) << second << endl; 
}

Clock reset() {
    return Clock(0, 0, 0); 
}
int main() { 
    Clock c1(12, 0, 5); 
    c1.show_time();
    
    c1 = reset(); 
    c1.show_time();
    
    Clock c2(c1); 
    c2.set_time(6);
    c2.show_time(); 
}

运行结果：

task4：

#include<iostream>

class X {
public:
    X();
    ~X();
    X(int m);
    X(const X& obj);
    X(X&& obj) noexcept;
    void show() const;

private:
    int data;
};

X::X() :data{ 42 } {
    std::cout << "default constructor called.\n";
}

X::~X() { 
    std::cout << "destructor called.\n";
}

X::X(int m) : data{ m } { 
    std::cout << "constructor called.\n";
}

X::X(const X& obj) : data{ obj.data } { 
    std::cout << "copy constructor called.\n"; 
}

X::X(X&& obj) noexcept : data{ obj.data } {
    std::cout << "move constructor called.\n"; 
}

void X::show() const {
    std::cout << data << std::endl;
}

int main() {
    X x1; 
    x1.show(); 
    
    X x2{2049}; 
    x2.show(); 
    
    X x3{x1}; 
    x3.show(); 
    
    X x4{ std::move(x2) }; 
    x4.show(); 
}

 task5:

#include <iostream>
#include <iomanip>

class Rectangle
{
public:
    Rectangle();
    Rectangle(double l,double w);
    Rectangle(const Rectangle&rect);
    ~Rectangle();
    
    double len() const;
    double wide() const;
    double area() const;
    double circumference() const;
    
    void resize(int times);
    void resize(int l_times,int w_times);
    
private:
    double length,width;
};
Rectangle::Rectangle():length{2.0},width{1.0}{}
Rectangle::Rectangle(double l,double w):length{l},width{w}{}
Rectangle::Rectangle(const Rectangle& rect):length{rect.length},width{rect.width}{}
Rectangle::~Rectangle(){}

double Rectangle::len() const{
    return length;
}
double Rectangle::wide() const{
    return width;
}
double Rectangle::area() const{
    return length*width;
};
double Rectangle::circumference() const{
    return 2*(length+width);
};

void Rectangle::resize(int times){
    length*=times;
    width*=times;
};

void Rectangle::resize(int l_times,int w_times){
    length*=l_times;
    width*=w_times;
};

void output(const Rectangle &rect) {
    using namespace std; 
    cout << "矩形信息: \n"; 
    cout << fixed << setprecision(2);
    cout<<setfill(' ')<<setw(6)<<left<<"长："<<rect.len()<<endl;
    cout<<setfill(' ')<<setw(6)<<left<<"宽："<<rect.wide()<<endl;
    cout<<setfill(' ')<<setw(6)<<left<<"面积："<<rect.area()<<endl;
    cout<<setfill(' ')<<setw(6)<<left<<"周长："<<rect.circumference()<<endl;
}

int main() { 
    Rectangle rect1;
    output(rect1); 
    
    Rectangle rect2(10, 5); 
    output(rect2); 
    
    Rectangle rect3(rect1);
    rect3.resize(2);
    output(rect3); 
    
    rect3.resize(5, 2); 
    output(rect3); 
}