#include<iostream>
#include<math.h>
#include<iomanip>

using namespace std;
const double PI=(2.0*asin(1.0));

int main(void)
{
	double x,y,z,role,half,max;
	double R,r,triple,area;
	int hujk=1;
	cin>>x>>y>>z>>role;
	while(x+y+z+role)
	{
		triple=x+y+z;
		half=triple*0.5;
		area=sqrt(half*(half-x)*(half-y)*(half-z));
		R=area*2.0/triple;
		if(x+y+z<=role)
			max=area;
		else if(2.0*PI*R>=role)
			max=role*role/(4.0*PI);
		else
		{
			r=(triple-role)/(triple/R-2.0*PI);
			max=area+PI*r*r-(r*r*area/(R*R));
		}
		cout<<"Case "<<hujk++<<": ";
		cout<<setiosflags(ios::fixed)<<setprecision(2)<<max<<endl;
		cin>>x>>y>>z>>role;
	}
	return 0;
}

• Re:最后那种情况是怎么推导出公式的啊？谢谢...... (0) rainstorm 2007-08-29 23:59:00