30 lines
711 B
C++
30 lines
711 B
C++
#include<iostream>
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#include<cmath>
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#include<cstdio>
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using namespace std;
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const double PI=acos(-1.0);
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int main()
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{
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double a,b,c,L;
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int cout=1;
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while(cin>>a>>b>>c>>L)
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{
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if(a==0&&b==0&&c==0&&L==0)
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break;
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double p=(a+b+c)/2.0;
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double S=sqrt(p*(p-a)*(p-b)*(p-c));
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double R=S/p;
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if(L>=a+b+c)
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printf("Case %d: %.2lf\n",cout++,S);
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else if(L<=PI*R*2)
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printf("Case %d: %.2lf\n",cout++,L*L/(4*PI));
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else
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{
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double r=R*(2*p-L)/(2*p-2*PI*R);
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double s=(r/R)*(r/R)*S;
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printf("Case %d: %.2lf\n",cout++,S-s+PI*r*r);
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}
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}
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return 0;
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}
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