声明 Point 类，有坐标 _ x，_ y 两个成员变量；对Point 类重载“++”（自增）、“--”（自减）运算符，实现对坐标值的改变。#include <iostream> using namespace std; class Point { int _x, _y; public: Point(int x=0, int y=0) : _x(x), _y(y) {} Point& operator++(); Point operator++(int); Point& operator--(); Point operator--(int); friend ostream& operator << (ostream& o, const Point& p); }; /********** Begin / / End **********/ ostream& operator << (ostream& o, const Point& p) { o << '(' << p._x << ", " << p._y << ')'; return o; } int main() { int x,y; cin>>x>>y; Point p(x, y); cout << p << endl; cout << p++ << endl; cout << ++p << endl; cout << p-- << endl; cout << --p << endl; return 0; }

以下是对 Point 类进行自增自减操作的完整代码实现：

#include <iostream> 
using namespace std; 

class Point { 
    int _x, _y; 
public: 
    Point(int x=0, int y=0) : _x(x), _y(y) {} 
    Point& operator++(); 
    Point operator++(int); 
    Point& operator--(); 
    Point operator--(int); 
    friend ostream& operator << (ostream& o, const Point& p); 
}; 

Point& Point::operator++() {
    ++_x;
    ++_y;
    return *this;
}

Point Point::operator++(int) {
    Point temp(*this);
    ++(*this);
    return temp;
}

Point& Point::operator--() {
    --_x;
    --_y;
    return *this;
}

Point Point::operator--(int) {
    Point temp(*this);
    --(*this);
    return temp;
}

ostream& operator << (ostream& o, const Point& p) {
    o << "(" << p._x << ", " << p._y << ")";
    return o;
}

int main() {
    int x, y;
    cin >> x >> y;
    Point p(x, y);
    cout << p << endl;
    cout << p++ << endl;
    cout << ++p << endl;
    cout << p-- << endl;
    cout << --p << endl;
    return 0;
}

以上代码演示了对 Point 类进行自增自减操作，并输出结果。