#include<stdio.h> int main() { double r,s; printf("enter r:\n"); scanf("%lf",&r); if(r<=0) printf("输入错误,重新输入"); else s=3.14*r*r; printf("s=%lf\n",s); return 0; }
posted on 2013-10-14 08:58 chcb111 阅读(134) 评论(0) 编辑 收藏 举报