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#include
#include
class shape
{
      public:
      virtual void display()=0;
};

class circle:public shape
{
      public:
             circle(double i):r(i)
             {}
             void display()
             {cout<<"圆的面积："<<3.14*r*r<      private:
              double r;
};

class square:public shape
{
      public:
             square(double i,double j):a(i),b(j)
             {}
             void display()
             {cout<<"正方形的面积"<      private:
              double a,b;
};

class triangle:public shape
{
      public:
             triangle(double i,double j):a(i),b(j)
             {}
             void display()
             {cout<<"三角形的面积："<      private:
              double a,b;
};

shape* factory()
{
       for(int m=0;m<1300;m++)
       for(int n=0;n<900;n++)
       {}
       int con=rand()%3;
       if(con==0) return new circle(rand()%30);
       if(con==1) return new square(rand()%30,rand()%30);
       if(con==2) return new triangle(rand()%30,rand()%30);
}


int main(int argc, char *argv[])
{
    srand(time(NULL));
    shape* array[50];
    for(int i=0;i<50;i++)
    array[i]=factory();
    for(int j=0;j<50;j++)
    array[j]->display();
    int m;
    cin>>m;
}

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