第十三周OJ

#include <iostream>

#include <cstdio>

#include <cmath>

#include <iomanip>

using namespace std;

class Point

{

public:

    Point(double a=0,double b=0,double c=0,double d=0):x1(a),y1(b),x2(c),y2(d) {}

    void  input();

    friend void output(Point &);

private:

    double x1;

    double y1;

    double x2;

    double y2;

};


void Point::input()
{
    cin>>x1;
    cin>>y1;
    cin>>x2;
    cin>>y2;
}
void output(Point &p)
{
    double m;
    m=sqrt((p.x1-p.x2)*(p.x1-p.x2)+(p.y1-p.y2)*(p.y1-p.y2));
    cout<<"There are "<<setiosflags(ios::fixed)<<setprecision(2)<<m<<" meters between xiaohui and her phone.";
}
//请补充函数 input output



//以下代码会自动添加到程序的末尾

int main()

{

    Point p1;

    p1.input();

    output(p1);

    return 0;

}

运行结果：

体会心得：一遍成功，有兄弟不失败.