立即学习:https://edu.csdn.net/course/play/25294/304632?utm_source=blogtoedu
#include<stdio.h>
int main()
{
//printf("格式控制字符,输出值参数表");
const double IP=3.1415926;
char ch;
double perimeter,area;
scanf("%lf",&r);
ch=getchat();
ch=ch+32;
perimeter=2*IP*r;
area=IP*r*r;
printf("%c\n%d\n%o\n",ch,ch,ch);
printf("%c\n%10d\n%o\n",ch,ch,ch);
printf("perimeter=%14.2f\narea=%10.2f\n",perimeter,area);
return 0;
}