阅读下列程序，写出运行结果： #include

#include<iostream>
using namespace std;
#include<cmath>
class Point
{
public :
Point( float x, float y )
{ a = x; b = y;  cout<<"点( "<<a<<", "<<b<<" )"; }
friend double d( Point &A, Point &B )
{ return sqrt((A.a-B.a)*(A.a-B.a)+(A.b-B.b)*(A.b-B.b)); }
private:
double a, b;
};
int main()
{
Point p1( 2, 3 );
cout << "到";
Point p2( 4, 5 );
cout << "的距离是：" << d( p1,p2 ) << endl;
}