Language: C++

#include <cmath>
#include <cstdio>

#define EPS 0.00000000001Lf

#define PI 3.141592653589793238462643383279Lf

int main()
{
    int q, x1, y1, x2, y2, x3, y3, x4, y4;
    
    scanf("%d", &q);
    
    for(int i = 0; i < q; i++)
    {
        scanf("%d", &x1);
        scanf("%d", &y1);
        scanf("%d", &x2);
        scanf("%d", &y2);
        scanf("%d"  &x3);
        scanf("%d", &y3);
        scanf("%d", &x4);
        scanf("%d", &x4);
        
        long double angle1 = atan2l(y2 - y1, x2 - x1);
        long double angle2 = atan2l(y4 - y3, x4 - x3);
        
        long double sa = abs(angle2 - angle1);
        
        if(sa < -EPS) { sa += PI * 2.0; }
        
        if(sa == PI * 0.5 || sa == PI * 1.5)
        {
            cout << 1 << endl;
        }
        else if(sa == PI || sa == 0)
        {
            cout << 2 << endl;
        }
        else
        {
            cout << 0 << endl;
        }
    }
    
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:21: error: invalid operands of types 'const char [3]' and 'int' to binary 'operator&'
   20 |         scanf("%d"  &x3);
      |               ~~~~  ^~~
      |               |      |
      |               |      int
      |               const char [3]
a.cc:4:13: error: unable to find numeric literal operator 'operator""Lf'
    4 | #define EPS 0.00000000001Lf
      |             ^~~~~~~~~~~~~~~
a.cc:30:18: note: in expansion of macro 'EPS'
   30 |         if(sa < -EPS) { sa += PI * 2.0; }
      |                  ^~~
a.cc:6:12: error: unable to find numeric literal operator 'operator""Lf'
    6 | #define PI 3.141592653589793238462643383279Lf
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:30:31: note: in expansion of macro 'PI'
   30 |         if(sa < -EPS) { sa += PI * 2.0; }
      |                               ^~
a.cc:6:12: error: unable to find numeric literal operator 'operator""Lf'
    6 | #define PI 3.141592653589793238462643383279Lf
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:32:18: note: in expansion of macro 'PI'
   32 |         if(sa == PI * 0.5 || sa == PI * 1.5)
      |                  ^~
a.cc:6:12: error: unable to find numeric literal operator 'operator""Lf'
    6 | #define PI 3.141592653589793238462643383279Lf
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:32:36: note: in expansion of macro 'PI'
   32 |         if(sa == PI * 0.5 || sa == PI * 1.5)
      |                                    ^~
a.cc:34:13: error: 'cout' was not declared in this scope
   34 |             cout << 1 << endl;
      |             ^~~~
a.cc:34:26: error: 'endl' was not declared in this scope
   34 |             cout << 1 << endl;
      |                          ^~~~
a.cc:6:12: error: unable to find numeric literal operator 'operator""Lf'
    6 | #define PI 3.141592653589793238462643383279Lf
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:36:23: note: in expansion of macro 'PI'
   36 |         else if(sa == PI || sa == 0)
      |                       ^~
a.cc:38:13: error: 'cout' was not declared in this scope
   38 |             cout << 2 << endl;
      |             ^~~~
a.cc:38:26: error: 'endl' was not declared in this scope
   38 |             cout << 2 << endl;
      |                          ^~~~
a.cc:42:13: error: 'cout' was not declared in this scope
   42 |             cout << 0 << endl;
      |             ^~~~
a.cc:42:26: error: 'endl' was not declared in this scope
   42 |             cout << 0 << endl;
      |                          ^~~~