uva 11731 - Ex-circles（几何）

题目链接：uva 11731 - Ex-circles

#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>

using namespace std;
const double pi = 4 * atan(1.0);

int A, B, C;

double getAngle(double a, double b, double c) {
double tmp = (a * a + b * b - c * c) / (2 * a * b);
return acos(tmp);
}

double getArea(double a, double b, double c) {
double s =(a + b + c) / 2;
return sqrt(s * (s - a) * (s - b) * (s - c));
}

int main () {
int cas = 1;
while (scanf("%d%d%d", &A, &B, &C) == 3) {
if (A == 0 || B == 0 || C == 0)
break;
double cornerA = getAngle(B, C, A);
double cornerB = getAngle(A, C, B);
double cornerC = getAngle(A, B, C);

double FAB = (pi - cornerA) / 2;
double FBA = (pi - cornerB) / 2;
double cornerF = pi - FAB - FBA;

double EAC = (pi - cornerA) / 2;
double ECA = (pi - cornerC) / 2;
double cornerE = pi - EAC - ECA;

double DBC = (pi - cornerB) / 2;
double DCB = (pi - cornerC) / 2;
double cornerD = pi - DBC - DCB;

double Sabc = getArea(A, B, C);
double Sabf = getArea(C, C / sin(cornerF) * sin(FAB), C / sin(cornerF) * sin(FBA));
double Sace = getArea(B, B / sin(cornerE) * sin(EAC), B / sin(cornerE) * sin(ECA));
double Sbcd = getArea(A, A / sin(cornerD) * sin(DBC), A / sin(cornerD) * sin(DCB));
double ans1 = Sabc + Sabf + Sace + Sbcd;

double ans2 = 0;
double Rf = Sabf * 2 / C;
ans2 += Rf * Rf * cornerF;
double Re = Sace * 2 / B;
ans2 += Re * Re * cornerE;
double Rd = Sbcd * 2 / A;
ans2 += Rd * Rd * cornerD;

printf("Case %d: %.2lf %.2lf\n", cas++, ans1, ans2 / 2);
}
return 0;
}