ZOJ-1090

最新推荐文章于 2020-08-16 14:41:00 发布

心之痕

最新推荐文章于 2020-08-16 14:41:00 发布

阅读量396

点赞数

CC 4.0 BY-SA版权

分类专栏： ZOJ 文章标签： ZOJ

本文链接：https://blog.youkuaiyun.com/xhldtc/article/details/17654311

ZOJ 专栏收录该内容

546 篇文章

订阅专栏

#include<stdio.h>
#include<math.h>
#define PI 3.141592653589793

int main()
{
	double ax, ay, bx, by, cx, cy;
	while (scanf("%lf %lf %lf %lf %lf %lf", &ax, &ay, &bx, &by, &cx, &cy) != EOF)
	{
		double a = sqrt((ax - bx) * (ax - bx) + (ay - by) * (ay - by));
		double b = sqrt((ax - cx) * (ax - cx) + (ay - cy) * (ay - cy));
		double c = sqrt((cx - bx) * (cx - bx) + (cy - by) * (cy - by));
		double r = a * b * c
				/ sqrt((a + b + c) * (a + b - c) * (a + c - b) * (b + c - a));
		printf("%.2lf\n", 2 * PI * r);
	}
	return 0;
}