2、定义点类 Point重载运算符＋、－、＝＝、！=、++、--、、实现两个点的相加、相减、相等、不等、自增、自减、输入和输出运算。

#include using namespace std;

class Point { private: double x, y; public: Point(double a = 0, double b = 0) : x(a), y(b) {} Point operator+(const Point& p) const { return Point(x + p.x, y + p.y); } Point operator-(const Point& p) const { return Point(x - p.x, y - p.y); } bool operator==(const Point& p) const { return x == p.x && y == p.y; } bool operator!=(const Point& p) const { return !(*this == p); } Point& operator++() { x++; y++; return *this; } Point operator++(int) { Point temp(*this); ++(*this); return temp; } Point& operator--() { x--; y--; return *this; } Point operator--(int) { Point temp(*this); --(*this); return temp; } friend istream& operator>>(istream& in, Point& p) { in >> p.x >> p.y; return in; } friend ostream& operator<<(ostream& out, const Point& p) { out << "(" << p.x << ", " << p.y << ")"; return out; } };

int main() { Point p1(1, 2), p2(3, 4); cout << "p1 = " << p1 << endl; cout << "p2 = " << p2 << endl; cout << "p1 + p2 = " << p1 + p2 << endl; cout << "p1 - p2 = " << p1 - p2 << endl; cout << "p1 == p2? " << (p1 == p2) << endl; cout << "p1 != p2? " << (p1 != p2) << endl; cout << "++p1 = " << ++p1 << endl; cout << "p1++ = " << p1++ << endl; cout << "p1 = " << p1 << endl; cout << "--p2 = " << --p2 << endl; cout << "p2-- = " << p2-- << endl; cout << "p2 = " << p2 << endl; cout << "请输入一个点的坐标："; cin >> p1; cout << "你输入的点是：" << p1 << endl; return 0;