【項目6-點結構體與枚舉】

#include "iostream"
#include "Cmath"
using namespace std;

enum SymmetricStyle {axisx,axisy,point};//分別表示按x軸, y軸, 原點對稱
struct Point
{
 double x;  // 橫座標
 double y;  // 縱座標
};
double distance(Point p1, Point p2);   // 兩點之間的距離
double distance0(Point p1);
Point symmetricAxis(Point p,SymmetricStyle style);   //返回對稱點

int main( )
{
 Point p1={1,5},p2={4,1},p;
 cout<<"兩點的距離為："<<distance(p1,p2)<<endl;
 cout<<"p1到原點的距離為："<<distance0(p1)<<endl;
 p=symmetricAxis(p1,axisx);
 cout<<"p1關於x軸的對稱點為："<<"("<<p.x<<", "<<p.y<<")"<<endl;
 p=symmetricAxis(p1,axisy);
 cout<<"p1關於y軸的對稱點為："<<"("<<p.x<<", "<<p.y<<")"<<endl;
 p=symmetricAxis(p1,point);
 cout<<"p1關於原點的對稱點為："<<"("<<p.x<<", "<<p.y<<")"<<endl;
 return 0;
}

// 求兩點之間的距離
double distance(Point p1,Point p2)
{
 double d;
 d=sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));
 return d;
}

// 求點到原點的距離
double distance0(Point p)
{
 double d;
 d=sqrt(p.x*p.x+p.y*p.y);
 return d;
}

// 求對稱點
Point symmetricAxis(Point p1,SymmetricStyle style)
{
 Point p;
 p.x=p1.x;
 p.y=p1.y;
 switch(style)
 {
 case axisx:
  p.y=-p1.y; break;
 case axisy:
  p.x=-p1.x; break;
 case point:
  p.x=-p1.x;p.y=-p1.y;
 }
 return p;
}