Language: C++

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace AthleteProgramming
{
    class Program
    {
        static void Main()
        {
            int n = int.Parse(Console.ReadLine());
            for(int i = 0; i < n; i++)
            {
                int[] array = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
                Sort(ref array);
                CheckRightTriangle(array);
            }
        }

        static void CheckRightTriangle(int[] array)
        {
            if (array[0] * array[0] == array[1] * array[1] + array[2] * array[2])
            {
                Console.WriteLine("YES");
            }
            else
            {
                Console.WriteLine("NO");
            }
        }

        static void Sort(ref int[] array)
        {
            for(int i = array.Length-1; i >= 0; i--)
            {
                for(int j = 0; j < i; j++)
                {
                    if (array[j] < array[j + 1])
                    {
                        Swap(ref array[j], ref array[j + 1]);
                    }
                }
            }
        }

        static void Swap(ref int a, ref int b)
        {
            int tmp = a;
            a = b;
            b = tmp;
        }

    }
}

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:2:7: error: expected nested-name-specifier before 'System'
    2 | using System.Collections.Generic;
      |       ^~~~~~
a.cc:3:7: error: expected nested-name-specifier before 'System'
    3 | using System.Linq;
      |       ^~~~~~
a.cc:4:7: error: expected nested-name-specifier before 'System'
    4 | using System.Text;
      |       ^~~~~~
a.cc:21:46: error: expected ',' or '...' before 'array'
   21 |         static void CheckRightTriangle(int[] array)
      |                                              ^~~~~
a.cc:33:26: error: 'ref' has not been declared
   33 |         static void Sort(ref int[] array)
      |                          ^~~
a.cc:33:26: error: two or more data types in declaration of 'parameter'
a.cc:33:35: error: expected ')' before 'array'
   33 |         static void Sort(ref int[] array)
      |                         ~         ^~~~~~
      |                                   )
a.cc:33:34: error: expected ';' at end of member declaration
   33 |         static void Sort(ref int[] array)
      |                                  ^
      |                                   ;
a.cc:33:36: error: 'array' does not name a type
   33 |         static void Sort(ref int[] array)
      |                                    ^~~~~
a.cc:47:26: error: 'ref' has not been declared
   47 |         static void Swap(ref int a, ref int b)
      |                          ^~~
a.cc:47:26: error: two or more data types in declaration of 'a'
a.cc:47:35: error: expected ')' before ',' token
   47 |         static void Swap(ref int a, ref int b)
      |                         ~         ^
      |                                   )
a.cc:47:37: error: variable or field 'ref' declared void
   47 |         static void Swap(ref int a, ref int b)
      |                                     ^~~
a.cc:47:37: error: expected ';' at end of member declaration
   47 |         static void Swap(ref int a, ref int b)
      |                                     ^~~
      |                                        ;
a.cc:47:45: error: expected ';' at end of member declaration
   47 |         static void Swap(ref int a, ref int b)
      |                                             ^
      |                                              ;
a.cc:47:46: error: expected unqualified-id before ')' token
   47 |         static void Swap(ref int a, ref int b)
      |                                              ^
a.cc:54:6: error: expected ';' after class definition
   54 |     }
      |      ^
      |      ;
a.cc: In static member function 'static void AthleteProgramming::Program::Main()':
a.cc:12:21: error: expected primary-expression before 'int'
   12 |             int n = int.Parse(Console.ReadLine());
      |                     ^~~
a.cc:15:20: error: structured binding declaration cannot have type 'int'
   15 |                 int[] array = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
      |                    ^~
a.cc:15:20: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:15:20: error: empty structured binding declaration
a.cc:15:23: error: expected initializer before 'array'
   15 |                 int[] array = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
      |                       ^~~~~
a.cc:16:22: error: 'ref' was not declared in this scope
   16 |                 Sort(ref array);
      |                      ^~~
a.cc:17:36: error: 'array' was not declared in this scope
   17 |                 CheckRightTriangle(array);
      |                                    ^~~~~
a.cc: In static member function 'static void AthleteProgramming::Program::CheckRightTriangle(int*)':
a.cc:23:17: error: 'array' was not declared in this scope
   23 |             if (array[0] * array[0] == array[1] * array[1] + array[2] * array[2])
      |                 ^~~~~
a.cc:25:17: error: 'Console' was not declared in this scope
   25 |                 Console.WriteLine("YES");
      |                 ^~~~~~~
a.cc:29:17: error: 'Console' was not declared in this scope
   29 |                 Console.WriteLine("NO");
      |                 ^~~~~~~