sgu162：Pyramids

题意：

给出四面体AB,AC,AD,BC,BD,CD,求体积。

分析：

#include <cstdio>#include <cmath>using namespace std;int main(){double a, b, c, d, e, f, D, E, F, V;scanf("%lf%lf%lf%lf%lf%lf", &a, &b, &c, &f, &e, &d);D = b*b+c*c-d*d;E = a*a+c*c-e*e;F = a*a+b*b-f*f;V = sqrt(a*a*b*b*c*c-(a*a*D*D+b*b*E*E+c*c*F*F)/4+D*E*F/4)/6;printf("%.4lf", V);return 0;}