实验1编写求圆面积的程序,要求当输入的半径r<=0时,提示输入错误,要求r为浮点型,r的数值是动态的由键盘输入;
#include<stdio.h> int main(void) { double n,s; printf("Enter n:"); scanf("%lf",&n); if(n<=0){ printf("You are worry.\n"); } else{ s=n*n*3.14; printf("f(%.2f)=%.2f\n",n,s); } return 0; }
#include<stdio.h> int main(void) { double n,s; printf("Enter n:"); scanf("%lf",&n); if(n<=0){ printf("You are worry.\n"); } else{ s=n*n*3.14; printf("f(%.2f)=%.2f\n",n,s); } return 0; }