uva 10522 - Height to Area（几何）

题目链接：uva 10522 - Height to Area

海伦公式。

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

using namespace std;
const double eps = 1e-9;

int main () {
int N, C = 0;
double a, b, c;
scanf("%d", &N);
while (N) {
scanf("%lf%lf%lf", &a, &b, &c);
if (fabs(a) < eps || fabs(b) < eps || fabs(c) < eps) {
N--;
printf("These are invalid inputs!\n");
continue;
}
a = 1 / a, b = 1 / b, c = 1 / c;
double t = a + b + c;
double S = t * (t - 2 * a) * (t - 2 * b) * (t - 2 * c);
if (S < 0) {
N--;
printf("These are invalid inputs!\n");
continue;
}
printf("%.3lf\n", 1 / sqrt(S));
}
return 0;
}