Problem G: 平面上的点和线——Point类、Line类 (III)
Description
在数学上,平面直角坐标系上的点用X轴和Y轴上的两个坐标值唯一确定,两点确定一条线段。现在我们封装一个“Point类”和“Line类”来实现平面上的点的操作。
根据“append.cc”,完成Point类和Line类的构造方法和show()方法,输出各Line对象和Point对象的构造和析构次序。
接口描述:
Point::show()方法:按格式输出Point对象。
Line::show()方法:按格式输出Line对象。
Input
输入的第一行为N,表示后面有N行测试样例。每行为两组坐标“x,y”,分别表示线段起点和终点的x坐标和y坐标,两组坐标间用一个空格分开,x和y的值都在double数据范围内。
Output
输出为多行,每行为一条线段,起点坐标在前终点坐标在后,每个点的X坐标在前,Y坐标在后,Y坐标前面多输出一个空格,用括号包裹起来。输出格式见sample。
C语言的输入输出被禁用。
Sample Input
4
0,0 1,1
1,1 2,3
2,3 4,5
0,1 1,0
Sample Output
Point : (1, -2) is created.
Point : (2, -1) is created.
Point : (0, 0) is created.
Point : (0, 0)
=========================
Point : (0, 0) is created.
Point : (1, 1) is created.
Line : (0, 0) to (1, 1) is created.
Line : (0, 0) to (1, 1)
Line : (0, 0) to (1, 1) is erased.
Point : (1, 1) is erased.
Point : (0, 0) is erased.
=========================
Point : (1, 1) is created.
Point : (2, 3) is created.
Line : (1, 1) to (2, 3) is created.
Line : (1, 1) to (2, 3)
Line : (1, 1) to (2, 3) is erased.
Point : (2, 3) is erased.
Point : (1, 1) is erased.
=========================
Point : (2, 3) is created.
Point : (4, 5) is created.
Line : (2, 3) to (4, 5) is created.
Line : (2, 3) to (4, 5)
Line : (2, 3) to (4, 5) is erased.
Point : (4, 5) is erased.
Point : (2, 3) is erased.
=========================
Point : (0, 1) is created.
Point : (1, 0) is created.
Line : (0, 1) to (1, 0) is created.
Line : (0, 1) to (1, 0)
Line : (0, 1) to (1, 0) is erased.
Point : (1, 0) is erased.
Point : (0, 1) is erased.
=========================
Point : (1, -2) is copied.
Point : (2, -1) is copied.
Line : (1, -2) to (2, -1) is created.
Point : (1, -2) is copied.
Point : (0, 0) is copied.
Line : (1, -2) to (0, 0) is created.
Point : (2, -1) is copied.
Point : (0, 0) is copied.
Line : (2, -1) to (0, 0) is created.
Point : (0, 0) is copied.
Point : (2, -1) is copied.
Line : (0, 0) to (2, -1) is created.
Line : (1, -2) to (2, -1)
Line : (1, -2) to (0, 0)
Line : (2, -1) to (0, 0)
Line : (0, 0) to (2, -1)
Line : (0, 0) to (2, -1) is erased.
Point : (2, -1) is erased.
Point : (0, 0) is erased.
Line : (2, -1) to (0, 0) is erased.
Point : (0, 0) is erased.
Point : (2, -1) is erased.
Line : (1, -2) to (0, 0) is erased.
Point : (0, 0) is erased.
Point : (1, -2) is erased.
Line : (1, -2) to (2, -1) is erased.
Point : (2, -1) is erased.
Point : (1, -2) is erased.
Point : (0, 0) is erased.
Point : (2, -1) is erased.
Point : (1, -2) is erased.
HINT
Append Code
#include<iostream>
using
namespace
std;
class
Point
{
private
:
double
x,y;
public
:
Point(
double
a=0,
double
b=0):x(a),y(b){cout<<
"Point : ("
<<x<<
", "
<<y<<
") is created."
<<endl;}
~Point(){cout<<
"Point : ("
<<x<<
", "
<<y<<
") is erased."
<<endl;}
Point(
const
Point &q){x=q.x;y=q.y;cout<<
"Point : ("
<<x<<
", "
<<y<<
") is copied."
<<endl;}
double
getX(){
return
x;}
double
getY(){
return
y;}
void
show(){cout<<
"Point : ("
<<x<<
", "
<<y<<
")"
<<endl;}
};
class
Line
{
private
:
Point xx,yy;
public
:
Line(
double
a,
double
b,
double
c,
double
d):xx(a,b),yy(c,d){cout<<
"Line : ("
<<xx.getX()<<
", "
<<xx.getY()<<
") to ("
<<yy.getX()<<
", "
<<yy.getY()<<
") is created."
<<endl;}
Line(Point &a,Point &b):xx(a),yy(b){cout<<
"Line : ("
<<xx.getX()<<
", "
<<xx.getY()<<
") to ("
<<yy.getX()<<
", "
<<yy.getY()<<
") is created."
<<endl;}
void
show(){cout<<
"Line : ("
<<xx.getX()<<
", "
<<xx.getY()<<
") to ("
<<yy.getX()<<
", "
<<yy.getY()<<
")"
<<endl;}
~Line(){cout<<
"Line : ("
<<xx.getX()<<
", "
<<xx.getY()<<
") to ("
<<yy.getX()<<
", "
<<yy.getY()<<
") is erased."
<<endl;}
};
int
main()
{
char
c;
int
num, i;
double
x1, x2, y1, y2;
Point p(1, -2), q(2, -1), t;
t.show();
std::cin>>num;
for
(i = 1; i <= num; i++)
{
std::cout<<
"=========================\n"
;
std::cin>>x1>>c>>y1>>x2>>c>>y2;
Line line(x1, y1, x2, y2);
line.show();
}
std::cout<<
"=========================\n"
;
Line l1(p, q), l2(p, t), l3(q, t), l4(t, q);
l1.show();
l2.show();
l3.show();
l4.show();
}