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#include #include class Point { int x,y; public: Point(int i,int j){x=i;y=j;} friend float distance(Point &p1,Point &p2); void disp() { cout<<"("<<x<<","<<y<<")"; } }; float distance(Point &p1,Point &p2) // 友元函数的实现 { float d; d=sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y)); return d; } void main() { Point p1(2,2),p2(5,5); p1.disp(); cout<<"与"; p2.disp(); cout<<"之间距离="<<distance(p1,p2)<<endl; } |
