直接用欧拉四面体体积公式
多case啊,题目没有明确说明,害我wa了好几次。
/************************************
* Author : binwin20 *
* Blog : blog.youkuaiyun.com/binwin20 *
************************************/
#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <cmath>
#include <cstring>
#include <iostream>
#include <queue>
#include <map>
#include <stack>
#include <string>
#include <algorithm>
#include <vector>
#include <list>
#include <deque>
#define LL long long
#define DB double
#define SI(a) scanf("%d",&a)
#define SD(a) scanf("%lf",&a)
#define SS(a) scanf("%s",a)
#define PF printf
#define MM(a,b) memset(a,b,sizeof(a))
#define REP(i,a,b) for(int i=a;i<b;i++)
#define REPD(i,a,b) for(int i=a;i>b;i--)
#define INF 0x3f3f3f3f
#define EPS 1e-8
#define bug puts("bug")
using namespace std;
#define N 100
DB q,p,r,l,m,n;
int main()
{
#ifndef ONLINE_JUDGE
freopen("in.txt","r",stdin);
#endif
while(~SD(p){
SD(q),SD(r),SD(n),SD(m),SD(l);
p = p*p;
q = q*q;
r = r*r;
l = l*l;
m = m*m;
n = n*n;
DB ans = sqrt((4*p*q*r-p*(q+r-l)*(q+r-l)-q*(r+p-m)
*(r+p-m)-r*(p+q-n)*(p+q-n)+(p+q-n)*(q+r-l)*(r+p-m)))/12.0;
PF("%.4lf\n",ans);
} return 0;
}