实验3

#include<stdio.h> int main() { double r,s; printf("Enter r:"); scanf("%Lf",&r); if(r<=0) { printf("sorry!it is wrong!'); } else { s=3.1415923*r*r; printf("s=%.2f\n",s); } return 0; }

 

转载于:https://www.cnblogs.com/liruijia199531/p/3367723.html