47 lines
815 B
C++
47 lines
815 B
C++
#include<iostream>
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using namespace std;
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class Figure{
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protected:
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double x,y;
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public:
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void set(double i, double j){
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x=i;y=j;
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}
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virtual void area()=0;
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};
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class Trianle:public Figure{
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public:
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void area(){
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cout<<"三角形面积："<<x*y*0.5<<endl;
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}
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};
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class Rectangle:public Figure{
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public:
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void area(){
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cout<<"这是矩形，它的面积是："<<x*y<<endl;
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}
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};
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int main(int argc, char const *argv[])
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{
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//定义抽象类指针
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Figure *pF=NULL;
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// Figure f1; 抽象类不能被实例化
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Rectangle r;
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Trianle t;
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t.set(10,20);
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pF=&t;
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pF->area();
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r.set(10,20);
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pF=&r;
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pF->area();
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//定义抽象类引用
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Figure &rF=t;
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rF.set(20,20);
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rF.area();
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system("pause");
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return 0;
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}
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