实验一

实验一：

#include <iostream>
#include <string>
#include <vector>
int main()
{
    using namespace std;
    string s1;
    string s2{ "c plus plus" };
    string s3{ s2 }; 
    string s4 = s2; 
    s1 = "oop";

    vector<string> v1;
    v1.push_back(s1); 
    v1.push_back(s2 + "1");
    v1.push_back(s3 + "2");
    v1.push_back(s4 + "3");
    cout << "output1: " << endl;
    for (auto item : v1)
        cout << item << endl;

    cout << "ouput2: ";
    for (auto p = v1.begin(); p != v1.end(); ++p)
        cout << *p << endl;

    cout << "output3: " << endl;
    for (auto i = 0; i < v1.size(); ++i)
        cout << v1[i] << endl;
    vector<string> v2{ v1.rbegin(), v1.rend() };

    cout << "v2: " << endl;
    for (auto item : v2)
        cout << item << endl;
}

#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <cstdlib>
#include <time.h>
template<typename T>
void output(const T& obj)
{
    for (auto item : obj)
        std::cout << item << " ";
    std::cout << std::endl;
}
int main()
{
    using namespace std;
    vector<int> v1{ 1, 9, 8, 4 };
    v1.insert(v1.begin(), 2022);
    v1.insert(v1.end(), 2023);
    cout << "v1: ";
    output(v1);

    v1.pop_back();
    v1.erase(v1.begin());
    cout << "v1: ";
    output(v1);
    vector<string> v2{ "1984","《动物农场》","《美丽新世界》" };
    cout << "v2: ";
    output(v2);
}

#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;
}

#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();
}

#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();
}

#include <iostream>
#include <iomanip>
 class Rectangle {
     public:
            Rectangle(double length = 2.0, double wideth = 1.0);
             Rectangle(const Rectangle & rect);
             ~Rectangle() = default;
             double len()const;
             double wide()const;
             double area()const;
             double circumference()const;
             void resize(auto t = 1);
             void resize(double l_t = 1.0, double w_t = 1.0);
    
        
     private:
             double l; double w; double times; double l_times; double w_times;
    
};
 Rectangle::Rectangle(double length, double wideth) :l{ length }, w{ wideth }{
     }
 Rectangle::Rectangle(const Rectangle & rect) {
         l = rect.l;
         w = rect.w;
    
        
}
 void Rectangle::resize(auto t) {
         times = t;
         l *= times;
         w *= times;
    
}
 void Rectangle::resize(double l_t, double w_t) {
         l_times = l_t;
         w_times = w_t;
         l *= l_times;
         w *= w_times;
    
}
 double Rectangle::len()const {
    
              return l;
    
}
 double Rectangle::wide()const {
    
              return w;
    
}
 double Rectangle::area()const {
         return l * w;
    
}
 double Rectangle::circumference()const {
         return 2 * (l + w);
    
}
 void output(const Rectangle & rect) {
         using namespace std;
         cout << "矩阵信息：\n";
         cout << fixed << setprecision(2);
         cout << "长：    " << rect.len() << endl
         << "宽：    " << rect.wide() << endl
         << "面积：    " << rect.area() << endl
         << "周长：    " << rect.circumference() << endl;
             cout << 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);
}