Language: C++

#include<iostream>
#include<math.h>
using namespace std;

int main()
{
    int n;
    int x1,x2,x3,y1,y2,y3;
    cin>>n;
    while(n--)
    {
        double x,y,r,dx,dy;
        cin>>x1<<y1<<x2<<y2<,x3<<y3;
        dx=(x2+x3-2*x1)/2;
        dy=(y2+y3-2*y1)/2;
        x=x1+dx;
        y=y1+dy;
        r=sqrt(dx*dx+dy*dy);
        printf("%.3f %.3f %.3f\n",x,y,r);
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:16: error: no match for 'operator<<' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'int')
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |         ~~~~~~~^~~~
      |            |     |
      |            |     int
      |            std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
a.cc:13:16: note: candidate: 'operator<<(int, int)' (built-in)
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |         ~~~~~~~^~~~
a.cc:13:16: note:   no known conversion for argument 1 from 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} to 'int'
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/string_view:763:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, basic_string_view<_CharT, _Traits>)'
  763 |     operator<<(basic_ostream<_CharT, _Traits>& __os,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:763:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/bits/basic_string.h:4077:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 4077 |     operator<<(basic_ostream<_CharT, _Traits>& __os,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:4077:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
In file included from /usr/include/c++/14/bits/memory_resource.h:38,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/cstddef:125:5: note: candidate: 'template<class _IntegerType> constexpr std::__byte_op_t<_IntegerType> std::operator<<(byte, _IntegerType)'
  125 |     operator<<(byte __b, _IntegerType __shift) noexcept
      |     ^~~~~~~~
/usr/include/c++/14/cstddef:125:5: note:   template argument deduction/substitution failed:
a.cc:13:12: note:   cannot convert 'std::cin.std::basic_istream<char>::operator>>(x1)' (type 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'}) to type 'std::byte'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |         ~~~^~~~
In file included from /usr/include/c++/14/bits/ios_base.h:46:
/usr/include/c++/14/system_error:339:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const error_code&)'
  339 |     operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
      |     ^~~~~~~~
/usr/include/c++/14/system_error:339:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:563:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, _CharT)'
  563 |     operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:563:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:573:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, char)'
  573 |     operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:573:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:579:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, char)'
  579 |     operator<<(basic_ostream<char, _Traits>& __out, char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:579:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:590:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, signed char)'
  590 |     operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:590:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:595:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, unsigned char)'
  595 |     operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:595:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:654:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const _CharT*)'
  654 |     operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:654:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
In file included from /usr/include/c++/14/ostream:1022:
/usr/include/c++/14/bits/ostream.tcc:307:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, const char*)'
  307 |     operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:307:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:671:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, const char*)'
  671 |     operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:671:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:684:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, const signed char*)'
  684 |     operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:684:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:689:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(basic_ostream<char, _Traits>&, const unsigned char*)'
  689 |     operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:689:5: note:   template argument deduction/substitution failed:
a.cc:13:18: note:   'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   13 |         cin>>x1<<y1<<x2<<y2<,x3<<y3;
      |                  ^~
/usr/include/c++/14/ostream:810:5: note: candidate: 'template<class _Ostream, class _Tp> _Ostream&& std::operator<<(_Ostream&&, const _Tp&)'
  810 |     operator<<(_Ostream&& __os, const _Tp& __x)
      |     ^~~~~~~~
/usr/include/c++/14/ostream:810:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/ostream: In substitution of 'temp