Language: C++

#include <bits/stdc++.h>
#define em3 ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
#define X real()
#define Y imag()
#define cross(a, b) ((conj(a) * (b)).Y)
#define dot(a, b) ((conj(a) * (b)).X)
#define EPS 1e-6
#define endl '\n'
long long mod = 1e9 + 7;
const int N = 1e5 + 5;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const double pi = acos(-1);
typedef complex <double> point;
typedef tuple<int, int, int> line;
typedef vector<point> polygon;
int x1 , y1 , x2 , y2 , diffx , diffy;
int main()
{
    em3
    cin >> x1 >> y1 >> x2 >> y2 ;
    diffx = x2 - x1;
    diffy = y2 - y1;
    cout << x2 - diffy << ' ' << y2 + diffx << ' ' << x1 - diffy << ' ' << y1 + diffx << endl;
    return 0;
}


Compiler output:
a.cc:19:10: error: 'int y1' redeclared as different kind of entity
   19 | int x1 , y1 , x2 , y2 , diffx , diffy;
      |          ^~
In file included from /usr/include/features.h:523,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/os_defines.h:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/c++config.h:683,
                 from /usr/include/c++/14/cassert:43,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:33,
                 from a.cc:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:257:1: note: previous declaration 'double y1(double)'
  257 | __MATHCALL (y1,, (_Mdouble_));
      | ^~~~~~~~~~
a.cc: In function 'int main()':
a.cc:23:15: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'double(double) noexcept')
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |     ~~~~~~~~~ ^~ ~~
      |         |        |
      |         |        double(double) noexcept
      |         std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double (*)(double) noexcept'
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(short int)y1' to 'short int&'
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'short unsigned int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(short unsigned int)y1' to 'short unsigned int&'
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(int)y1' to 'int&'
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'unsigned int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(unsigned int)y1' to 'unsigned int&'
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(long int)y1' to 'long int&'
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long unsigned int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(long unsigned int)y1' to 'long unsigned int&'
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(long long int)y1' to 'long long int&'
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'long long unsigned int' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(long long unsigned int)y1' to 'long long unsigned int&'
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'void*' [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
a.cc:23:18: error: cannot bind rvalue '(void*)y1' to 'void*&'
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
   23 |     cin >> x1 >> y1 >> x2 >> y2 ;
      |                  ^~
      |                  |
      |                  double (*)(double) noexcept
/usr/include/c++/14/istream:126:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>; __ios_type = std::basic_ios<char>]' (near match)
  126 |       operator>>(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:126:7: note:   conversion of argument 1 would be ill-formed:
a.cc:23:18: error: invalid conversion from 'double (*)(double) noexcept' to 'std::basic_istream<char>::__ios_type& (*)(std::