4点共面

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define  ll long long
 4 struct zb{
 5 int x,y,z;
 6 
 7 }a,b,c,d;
 8 int main()
 9 {int t;cin>>t;
10 while(t--)
11 {
12     cin>>a.x>>a.y>>a.z;
13      cin>>b.x>>b.y>>b.z;
14       cin>>c.x>>c.y>>c.z;
15        cin>>d.x>>d.y>>d.z;
16        zb q,w,e;
17        q.x=a.x-b.x;q.y=a.y-b.y;q.z=a.z-b.z;
18        w.x=a.x-c.x;w.y=a.y-c.y;w.z=a.z-c.z;
19        e.x=a.x-d.x;e.y=a.y-d.y;e.z=a.z-d.z;
20          int x,y,z;
21          x=q.x*(w.y*e.z-w.z*e.y);
22          y=q.y*(e.x*w.z-w.x*e.z);
23          z=q.z*(w.x*e.y-e.x*w.y);
24          if(x+y+z==0)cout<<"Yes\n";
25          else cout<<"No\n";
26 }
27 
28 
29 
30 }