题解 | #牛牛的圆#
牛牛的圆
https://www.nowcoder.com/practice/75a202e826d048a39824ec694b5ce7e3
#include <stdio.h>
#include<math.h>
int main()
{
int r = 0;
scanf("%d", &r);
float area = 0;
//area = 3.14 * (r *r);
//或者用pow函数
area = 3.14 * pow(r, 2);
printf("%.2f", area);
return 0;
}
