C 程序设计基础(第5版)(上)周霭如【1 基本数据与表达式】课件.ppt

++++,是由字、词和语法规则构成的指令系统程序设计 根据特定的问题,使用某种程序设计语言,设计出计算机执行的指令序列主要完成两方面工作:数据描述(2):输入圆的半径,求圆的周长和面积数据描述: 半径,周长,面积均用实型数表示数据处理: 输入半径r; 计算周长=2*π*r; 计算面积=π*r2; 输出半径,周长,面积;++-1方法一,用结构化方法编程,求圆的周长和面积//countthegirthandareaofcircle#include<iostream>usingnamespacestd;intmain(){doubler,girth,area; constdoublePI=;cout<<"Pleaseinputradius:\n";cin>>r;girth=2*PI*r;area=PI*r*r;cout<<"radius="<<r<<endl;cout<<"girth="<<girth<<endl;cout<<"area="<<area<<endl;}例1-1方法一,用结构化方法编程,求圆的周长和面积//countthegirthandareaofcircle#include<iostream>usingnamespacestd;intmain(){doubler,girth,area;constdoublePI=;cout<<"Pleaseinputradius:\n";cin>>r;girth=2*PI*r;area=PI*r*r;cout<<"radius="<<r<<endl;cout<<"girth="<<girth<<endl;cout<<"area="<<area<<endl;}数据描述例1-1方法一,用结构化方法编程,求圆的周长和面积//countthegirthandareaofcircle#include<iostream>usingnamespacestd;intmain(){doubler,girth,area;constdoublePI=;cout<<"Pleaseinputradius:\n";cin>>r;girth=2*PI*r;area=PI*r*r;cout<<"radius="<<r<<endl;cout<<"girth="<<girth<<endl;cout<<"area="<<area<<endl;}数据处理例1-1方法一,用结构化方法编程,求圆的周长和面积//countthegirthandareaofcircle#include<iostream>usingnamespacestd;intmain(){doubler,girth,area;constdoublePI=;cout<<"Pleaseinputradius:\n";cin>>r;girth=2*PI*r;area=PI*r*r;cout<<"radius="<<r<<endl;cout<<"girth="<<girth<<endl;cout<<"area="<<area<<endl;}输入数据例1-1方法一,用结构化方法编程,求圆的周长和面积//countthegirthandareaofcircle#include<iostream>usingnamespacestd;intmain(){doubler,girth,area;constdoublePI=;cout<<"Pleaseinputradius:\n";cin>>r;girth=2*PI*r;area=PI*r*r;cout<<"radius="<<r<<endl;cout<<"girth="<<girth<<endl;cout<<"area="<<area<<endl;}计算周长和面积例1-1方法一,用结构化方法编程,求圆的周长和面积//countthegirthandareaofcircle#include<iostream>usingnamespacestd;intmain(){doubler,girth,area;constdoublePI=;cout<<"Pleaseinputradius:\n";cin>>r;girth=2*PI*r;area=PI*r*r;cout<<"radius="<<r<<endl;cout<<"girth="<<girth<<endl;cout<<"area="<<area<