两点间距离

/*
*Copyright (c) 2016
*All rights reserved.
*文件名称：test.cpp
*作    者：史红浩
*完成日期：2016年 5 月 9 日
*版 本 号：v1.0
*/
#include<iostream>
#include<Cmath>
using namespace std;
class CPoint
{
private:
double x;
double y;
public:
CPoint(double xx=0,double yy=0):x(xx),y(yy){}
friend void dist(CPoint &,CPoint &);
};
void dist(CPoint &p1,CPoint &p2)
{
double l;
l=sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));
cout<<l<<endl;
}
int main()
{
int n1,n2,m1,m2;
cout<<"请输入点t1:";
cin>>n1>>n2;
cout<<"请输入点t2:";
cin>>m1>>m2;
CPoint t1(n1,n2),t2(m1,m2);
dist(t1,t2);
return 0;
}