實(shí)踐教程-實(shí)驗(yàn)純虛函數(shù)

一、實(shí)驗(yàn)?zāi)?/p>

實(shí)驗(yàn)二十五純虛函二、實(shí)驗(yàn)內(nèi)1先定義一個(gè)抽象基類CElement，提供顯示、求面積等公共接口（虛函數(shù)，派生出CPoint、CLine、CCircle等圖形元素類，并重定義（override）這些虛函數(shù)，完成各自的任務(wù)。再定義一個(gè)CElemList鏈表類，存放CElement的派生類。然后定義main()函數(shù)，生成多個(gè)圖形元素鏈表中，通過鏈表的頭指針逐個(gè)訪在這里，CElement是抽象基類，它不能提供具體的顯示等操作，應(yīng)將其成[程序#include<cmath>usingnamespacestd;double classCElement{virtualvoidShow()=0;virtualdoubleArea()=0;CElement*Next;//預(yù)留，可以將各元素成classCPoint:publicCElement{friendclassCLine;doublex,y;CPoint(){x=0;y=0;CPoint(doublexv,doubleyv){x=xv;y=yv;}doubleArea(){return0;}void}classCCircle:publioint{doubleradius;CCircle(){x=0;y=0;radius=0;CCircle(doublexv,doubleyv,doublevv):CPoint(xv,yv){radius=vv;}doublereturn}void}classCLine:publicCElement{CPointstart,end;CLine(doublexv1,doubleyv1,doublexv2,doubleyv2):start(xv1,yv1),end(xv2,yv2){};double}doubleArea(){return0;}voidShow(){cout<<"startpoint:\n";cout<<"endpoint:\n";}classCElemList{CElement //voidInsert(CElementintDelete(CElement//voidCElement*GetHead(){returnhead;//element.h#include<iostream>#include"element.h"CElement*p=p2=p=p->Next;deletep2;}return}elem->Next= //在表頭結(jié)head=}intCElemList::Delete(CElement*elem){CElement*p1=head,*p2=head; if(p1!=head)p2->Next=p1->Next;elsehead=head->Next;deletep1;return1;}elsereturn}voidCElemList::Show(){CElement*p= p=p-}return}#include<iostream>usingnamespacestd;#include"element.h"intmain(){CElemList CElement*p1=newCLine(100,100,100,200);p1=newCCircle(200,100,20);return0;}類的框架，并非是要建立一個(gè)完整的類。要求首先定義定積分抽象基類同時(shí)包括一個(gè)計(jì)算積分的純虛函數(shù)：virtualvoidinteg