hu3201 Build a Fence 解题报告
链接:http://acm.hdu.edu.cn/showproblem.php?pid=3201
思路: 周长一定, 圆的面积最大~
View Code
1 #include <cmath> 2 #include <cstdio> 3 using namespace std; 4 const double PI = acos(-1.0); 5 int n; 6 int main() { 7 while (scanf("%d", &n) != EOF) { 8 if (n == 0) break; 9 printf("%.2lf\n", (n / PI) * (n / PI) * PI * 0.5); 10 } 11 return 0; 12 }