#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;
}
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#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);
}
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#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;
}
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#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();
}
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#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();
}
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