#include <iostream> using namespace std; // 点类 class Pointer { private: int x; // x 坐标 int y; // y 坐标 public: void setX(int x) { this->x = x; } int getX() { return x; } void setY(int y) { this->y = y; } int getY() { return y; } friend class Circle; }; // 圆类 class Circle { private: Pointer center; // 圆心 int radius; // 半径 public: void setCenter(int x, int y) { center.setX(x); center.setY(y); } void setRadius(int radius) { this->radius = radius; } // write your code here...... void isPointerInCircle(Pointer &a) { int d; d = (a.x - center.x)*(a.x - center.x) + (a.y - center.y)*(a.y - center.y); if(d > radius*radius)cout << "out" << endl; else if(d == radius*radius) cout << "on" << endl; else cout << "in" <<endl; } }; int main() { // 键盘输入点的坐标 int x, y; cin >> x; cin >> y; // 创建一个点 Pointer p; p.setX(x); p.setY(y); // 创建一个圆 Circle c; c.setCenter(5, 0); c.setRadius(5); // 判断点和圆的关系 c.isPointerInCircle(p); return 0; }