Object-oriented 2

[Cpp]/** Copyright (c) 2012, School of Computer Science, Yantai University * All rights reserved. * file name: 123.cpp * Author: Qiu xuewei * Completion Date: July 15, March 15, 2013 * version No.: v1.0 * input Description: none * Problem description: Object-oriented, program output: slightly * Problem Analysis: slightly Algorithm Design: slightly */# include <iostream> # define pi 3.14 using namespace std; class Circle {private: double radius; public: void setRadius (double); double area (); double circumference () ;}; void Circle: setRadius (double r) {radius = r;} do Uble Circle: area () {double s; s = radius * pi; return s;} double Circle: circumference () {double l; l = 2 * radius * pi; return l;} int main () {double r; cout <"Enter the roller rink radius:"; cin> r; Circle c; c. setRadius (r); cout <"The cost of the roller rink is" <20 * c. area () + 35 * c. circumference () <"Yuan. "<Endl; return 0 ;}