第十三周实验报告(3)
2012-05-16 11:09
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/* 程序头部注释开始 * 程序的版权和版本声明部分 * Copyright (c) 2012, 烟台大学计算机学院学生 * Copyright (c) 2012, 烟台大学计算机学院学生 * All rights reserved. * 文件名称: * 作 者: 李瑞 * 完成日期: 2012 年5 月 15日 * 版 本 号: v1.0 * 对任务及求解方法的描述部分 * 输入描述:…… * 问题描述:…… * 程序输出:…… * 程序头部的注释结束*/
//【任务3】写一个程序,定义抽象基类Shape,由它派生出3个派生类,Circle(圆形)、Rectangle(矩形)、Triangle(三角形)。//用如下的mian()函数,求出定义的几个几何体的面积和。#include<iostream>using namespace std;const double PI = 3.14159;class Shape{public:virtual double area() const =0;};class Circle: public Shape{public:Circle(double radius);virtual double area() const;protected:double radius; //半径};class Rectangle: public Shape{public:Rectangle(double length, double width);virtual double area() const;protected:double length;double width;};class Triangle: public Shape{public:Triangle(double base, double height);virtual double area() const;protected:double base;double height;};Circle::Circle(double radius){this->radius = radius;}double Circle::area() const{return PI * radius * radius;}Rectangle::Rectangle(double length, double width){this->length = length;this->width = width;}double Rectangle::area() const{return length * width;}Triangle::Triangle(double base, double height){this->base = base;this->height = height;}double Triangle::area() const{return 0.5 * base * height;}int main(){Circle c1(12.6), c2(4.9); //建立Circle类对象c1,c2,参数为圆半径Rectangle r1(4.5, 8.4), r2(5.0, 2.5); //建立Rectangle类对象r1,r2,参数为矩形长、宽Triangle t1(4.5, 8.4), t2(3.4, 2.8); //建立Triangle类对象t1,t2,参数为三角形底边长与高Shape *pt[6] = {&c1, &c2, &r1, &r2, &t1, &t2}; //定义基类指针数组pt,各元素指向一个派生类对象double areas = 0.0; //areas为总面积for(int i = 0; i < 6; i++){areas = areas + pt[i]->area();}cout << "totol of all areas=" << areas << endl; //输出总面积system("pause");return 0;}结果:totol of all areas=648.148请按任意键继续. . .