Language: C++

using System;
class AIDU0021
    {
        public static void Main(){
            double[] facets = new double[8], VAB = new double[2],VCD = new double[2];
            string[] facetstr = new string[8];
            int N=int.Parse(Console.ReadLine()),i=0;
            bool[] result=new bool[N];
            for (int l = 0; l<N; l++) {
                facetstr=Console.ReadLine().Split();
                for (i = 0; i<8; i++) 
                    facets[i]=double.Parse(facetstr[i]);
                for (i = 0; i<2; i++) {
                    VAB[i]=facets[i+2]-facets[i];
                    VCD[i]=facets[i+6]-facets[i+4];
                }
                result[l]= VAB[0]*VCD[1]-VAB[1]*VCD[0]==0.0;
            }
            for (int l = 0; l<N; l++) Console.WriteLine(result[l] ? "YES" : "NO");
        }
    }

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:4:15: error: expected ':' before 'static'
    4 |         public static void Main(){
      |               ^~~~~~~
      |               :
a.cc:21:6: error: expected ';' after class definition
   21 |     }
      |      ^
      |      ;
a.cc: In static member function 'static void AIDU0021::Main()':
a.cc:5:19: error: structured binding declaration cannot have type 'double'
    5 |             double[] facets = new double[8], VAB = new double[2],VCD = new double[2];
      |                   ^~
a.cc:5:19: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:5:19: error: empty structured binding declaration
a.cc:5:22: error: expected initializer before 'facets'
    5 |             double[] facets = new double[8], VAB = new double[2],VCD = new double[2];
      |                      ^~~~~~
a.cc:6:13: error: 'string' was not declared in this scope
    6 |             string[] facetstr = new string[8];
      |             ^~~~~~
a.cc:6:20: error: expected primary-expression before ']' token
    6 |             string[] facetstr = new string[8];
      |                    ^
a.cc:7:19: error: expected primary-expression before 'int'
    7 |             int N=int.Parse(Console.ReadLine()),i=0;
      |                   ^~~
a.cc:8:17: error: structured binding declaration cannot have type 'bool'
    8 |             bool[] result=new bool[N];
      |                 ^~
a.cc:8:17: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:8:17: error: empty structured binding declaration
a.cc:8:20: error: expected initializer before 'result'
    8 |             bool[] result=new bool[N];
      |                    ^~~~~~
a.cc:10:17: error: 'facetstr' was not declared in this scope
   10 |                 facetstr=Console.ReadLine().Split();
      |                 ^~~~~~~~
a.cc:10:26: error: 'Console' was not declared in this scope
   10 |                 facetstr=Console.ReadLine().Split();
      |                          ^~~~~~~
a.cc:11:22: error: 'i' was not declared in this scope
   11 |                 for (i = 0; i<8; i++)
      |                      ^
a.cc:12:21: error: 'facets' was not declared in this scope
   12 |                     facets[i]=double.Parse(facetstr[i]);
      |                     ^~~~~~
a.cc:12:31: error: expected primary-expression before 'double'
   12 |                     facets[i]=double.Parse(facetstr[i]);
      |                               ^~~~~~
a.cc:13:22: error: 'i' was not declared in this scope
   13 |                 for (i = 0; i<2; i++) {
      |                      ^
a.cc:14:21: error: 'VAB' was not declared in this scope
   14 |                     VAB[i]=facets[i+2]-facets[i];
      |                     ^~~
a.cc:14:28: error: 'facets' was not declared in this scope
   14 |                     VAB[i]=facets[i+2]-facets[i];
      |                            ^~~~~~
a.cc:15:21: error: 'VCD' was not declared in this scope
   15 |                     VCD[i]=facets[i+6]-facets[i+4];
      |                     ^~~
a.cc:17:17: error: 'result' was not declared in this scope
   17 |                 result[l]= VAB[0]*VCD[1]-VAB[1]*VCD[0]==0.0;
      |                 ^~~~~~
a.cc:17:28: error: 'VAB' was not declared in this scope
   17 |                 result[l]= VAB[0]*VCD[1]-VAB[1]*VCD[0]==0.0;
      |                            ^~~
a.cc:17:35: error: 'VCD' was not declared in this scope
   17 |                 result[l]= VAB[0]*VCD[1]-VAB[1]*VCD[0]==0.0;
      |                                   ^~~
a.cc:19:39: error: 'Console' was not declared in this scope
   19 |             for (int l = 0; l<N; l++) Console.WriteLine(result[l] ? "YES" : "NO");
      |                                       ^~~~~~~
a.cc:19:57: error: 'result' was not declared in this scope
   19 |             for (int l = 0; l<N; l++) Console.WriteLine(result[l] ? "YES" : "NO");
      |                                                         ^~~~~~