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本文是我做家教时的题目，希望没有版权问题。这是一个简单的C++类继承的例子，继承关系为图形->三角形->左（右）三角形，图形->矩形->正方形，里面还包括填充图形等类，同时展示了多态性。
注意，本程序需要用支持C++11的编译器编译，如VS2013，DEV C++等
1、主程序
//prog.cpp
#include "shapes.hpp"
using namespace std;
int main() {
vector<Rectangle*> rectangles;
rectangles.push_back(new Rectangle(3, 5)); // Die beiden Argumente geben Breite und Höhe an
rectangles.push_back(new Rectangle(5, 7)); // Die beiden Argumente geben Breite und Höhe an
rectangles.push_back(new FilledRectangle(7, 5));// Die beiden Argumente geben Breite und Höhe an
rectangles.push_back(new Square(6)); // Das Argument gibt die Seitenlänge an
rectangles.push_back(new FilledSquare(7)); // Das Argument gibt die Seitenlänge an
// for (Rectangle* r : rectangles) {
// r->print();
// }
vector<Triangle*> triangles;
// Bei den Dreiecken soll es sich um gleichschenklige, rechtwinklige
// Dreiecke handeln. Der rechte Winkel wird von von den gleichlangen Seiten
// eingeschlossen.
triangles.push_back(new LeftTriangle(10)); // Das Argument gibt die Länge der
triangles.push_back(new RightTriangle(7)); // beiden gleichlangen Seiten an.
// for (Triangle* t : triangles) {
// t->print();
// }
vector<Shape*> shapes;
// für jedes r in rectangles
for (Rectangle* r : rectangles) {
shapes.push_back(r);
}
// für jedes t in triangles
for (Triangle* t : triangles) {
shapes.push_back(t);
}
// für jedes s in shapes
for (Shape *s: shapes) {
processShape(*s);
}
////////////////////////////
for (Shape *s: shapes) {
delete s;
}
}
2、头文件，hpp文件，现在已经升级为hpp了，呵呵
//shapes.hpp
#ifndef SHAPES_HPP
#define SHAPES_HPP
#include <iostream>
#include <vector>
class Shape
{
public:
//virtual void print() const = 0;
virtual void print() const;
virtual double area() const = 0;
virtual double perimeter() const = 0;
};
class Rectangle:public Shape
{
protected:
int width;
int height;
public:
Rectangle(int width, int height);
virtual void print() const;
virtual double area() const;
virtual double perimeter() const;
};
class FilledRectangle:public Rectangle
{
public:
FilledRectangle(int width, int height);
virtual void print() const;
};
class Square:public Rectangle
{
public:
Square(int length);
};
class FilledSquare:public FilledRectangle
{
public:
FilledSquare(int length);
};
class Triangle:public Shape
{
protected:
int length;
////////////////
public:
Triangle(int length);
virtual double area() const;
virtual double perimeter() const;
};
class LeftTriangle:public Triangle
{
public:
LeftTriangle(int lenght);
virtual void print() const;
};
class RightTriangle:public Triangle
{
public:
RightTriangle(int length);
virtual void print() const;
};
void processShape(const Shape& s);
#endif
3、cpp文件
////shapes.cpp
#include "shapes.hpp"
using namespace std;
void Shape::print() const
{
//Error;
}
Rectangle::Rectangle(int width, int height)
{
this->width = width;
this->height = height;
}
void Rectangle::print()const
{
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
if (i > 0 && i < height - 1 && j > 0 && j < width - 1)
printf(" ");
else
printf("*");
}
printf("\n");
}
}
double Rectangle::area() const
{
return width * height;
}
double Rectangle::perimeter() const
{
return 2 * (width + height);
}
FilledRectangle::FilledRectangle(int width, int height)
:Rectangle(width, height)
{
}
void FilledRectangle::print() const
{
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
printf("*");
}
printf("\n");
}
}
Square::Square(int length)
:Rectangle(length, length)
{
}
FilledSquare::FilledSquare(int length)
:FilledRectangle(length, length)
{
}
Triangle::Triangle(int length)
{
this->length = length;
}
double Triangle::area() const
{
return length * length / 2;
}
double Triangle::perimeter() const
{
return (2 + 1.414) * length;
///////////////
}
LeftTriangle::LeftTriangle(int length)
:Triangle(length)
{
}
void LeftTriangle::print() const
{
for (int i = 0; i < length; i++)
{
for (int j = 0; j < length; j++)
{
if (j == 0 || i == j || i == length - 1)
printf("*");
else
printf(" ");
}
printf("\n");
}
}
RightTriangle::RightTriangle(int length)
:Triangle(length)
{
}
void RightTriangle::print()const
{
for (int i = 0; i < length; i++)
{
for (int j = 0; j < length; j++)
{
if (j == length - 1 || length - i - 1 == j || i == length - 1)
printf("*");
else
printf(" ");
}
printf("\n");
}
}
void processShape(const Shape& s) {
s.print();
cout << "Flaeche: " << s.area() << endl;
cout << "Umfang: " << s.perimeter() << endl;
cout << endl << endl;
}
结果如下：
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原文地址：http://www.cnblogs.com/lishuai0214/p/4245543.html
