12周任务4

#include<iostream>   #include<Cmath>   #include<iomanip>    using namespace std;    class Point   {  public:      Point(){x = 0; y = 0;}      Point(double x0,double y0) {x = x0; y = y0;}      ~Point(){}      double getx(){return x;}      double gety(){return y;}      friend ostream & operator << (ostream &, Point &);      double x, y;    };      class Circle: public Point   {  public:      Circle(){radii = 0;}      Circle(double x0, double y0, double r);        ~Circle(){};      friend int locate(Point p1, Circle c1);      double Length(Point p1, Point p2);      friend ostream & operator << (ostream &, Circle &);      friend bool operator > (Circle & c1, Circle & c2);      friend bool operator < (Circle & c1, Circle & c2);      friend bool operator >= (Circle & c1, Circle & c2);      friend bool operator <= (Circle & c1, Circle & c2);      friend bool operator == (Circle & c1, Circle & c2);      friend bool operator != (Circle & c1, Circle & c2);      friend void crossover_point1(Point & p1, Circle & c1, Point & p4, Point & p5);  protected:      double radii;  };    Circle::Circle(double x0, double y0, double r):Point(x0, y0),radii(r){}    void crossover_point1(Point & p1, Circle & c1, Point & p4, Point & p5)  {      double x0 =(c1.x-p1.x)*c1.radii/sqrt((c1.x-p1.x)*(c1.x-p1.x)+(c1.y-p1.y)*(c1.y-p1.y));      double y0 =(c1.y-p1.y)*c1.radii/sqrt((c1.x-p1.x)*(c1.x-p1.x)+(c1.y-p1.y)*(c1.y-p1.y));        p4.x=c1.x+x0;      p4.y=c1.y+y0;        p5.x=c1.x-x0;      p5.y=c1.y-y0;  }    int locate(Point p1, Circle c1)  {      double length = sqrt((p1.x - c1.x) * (p1.x - c1.x) + (p1.y - c1.y) * (p1.y - c1.y));        if(length < c1.radii)                return 1;           else if(length == c1.radii)                return 0;           else               return -1;       }    ostream & operator << (ostream & out, Point & p)  {      out << "(" << p.x << "," << p.y << ")" << endl;       return out;  }    ostream & operator << (ostream & out, Circle & c)  {      out << "以" << "(" << c.x << "," << c.y << ")为圆心，" << "半径为 " << c.radii << "的圆 " << endl;      return out;  }    bool operator > (Circle & c1, Circle & c2)  {      if(c1.radii > c2.radii)              return true;         else             return false;      }    bool operator < (Circle & c1, Circle & c2)  {      if(c1.radii < c2.radii)           return true;      else          return false;  }    bool operator >= (Circle & c1, Circle & c2)  {      if(c1.radii >= c2.radii)           return true;       else          return false;  }    bool operator <= (Circle & c1, Circle & c2)  {      if(c1.radii <= c2.radii)          return true;      else           return false;  }    bool operator == (Circle & c1, Circle & c2)  {      if(c1.radii == c2.radii)           return true;      else           return false;  }    bool operator != (Circle & c1, Circle & c2)  {      if(c1.radii != c2.radii)            return true;       else          return false;  }    int main( )  {      Circle c1(3, 2, 4), c2(4, 5, 5);      //c2应该大于c1      Point p1(1, 1), p2(3, -2), p3(7, 3);  //分别位于c1内、上、外        cout << "圆c1: " << c1;      cout << "点p1: " << p1;      cout << "点p1在圆c1之" << ((locate(p1, c1)>0)? "外" :((locate(p1, c1)<0)? "内" : "上" )) << endl;      cout << "点p2: " << p2;      cout << "点p2在圆c1之" << ((locate(p2, c1)>0)? "外" :((locate(p2, c1)<0)? "内" : "上" )) << endl;        cout << "点p3: " << p3;      cout << "点p3在圆c1之" << ((locate(p3, c1)>0)? "外" :((locate(p3, c1)<0)? "内" : "上" )) << endl;      cout << endl;         cout << "圆c1: " << c1;      if(c1 > c2)      {          cout << "大于" << endl;      }      if(c1 < c2)      {           cout << "小于" << endl;       }      if(c1 >= c2)      {          cout << "大于等于" << endl;      }      if(c1 <= c2)      {          cout << "小于等于" << endl;       }      if(c1 == c2)      {          cout << "等于" << endl;       }      if(c1 != c2)      {          cout << "不等于" << endl;       }      cout << "圆c2: " << c2;      cout << endl;         Point p4, p5;      crossover_point1(p1, c1, p4, p5);        cout << "点p1: " << p1;      cout << "与圆c1: " << c1;      cout << "的圆心相连，与圆交于两点，分别是：" << endl;      cout << "交点: " << p4;      cout << "交点: " << p5;      cout << endl;         system("pause");      return 0;  }  

运行结果：

感言：大的程序无外乎一个个小地程序，不想被落下，哎。。。。。。