Language: C++

#include <iostream>

using namespace std;

int main()
{
  int x = 0;
  int data1[3000],data2[3000];
  
  while(1)
    {
      cin >> data1[x] >> " " >> data2[x];
      
      if(data1[x] == 0 && data2[x] == 0)
	{
	  break;
	}
      x++;
    }
  for(int k =0;k < x;k++)
    {
      if(data1[k] > data2[k])
	{
	  cout << data1[k] << " " << data2[k] << endl;
	}
      else
	{
	  cout << data2[k] << " " << data1[k] << endl;
	}
	
    }
  return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:12:23: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'const char [2]')
   12 |       cin >> data1[x] >> " " >> data2[x];
      |       ~~~~~~~~~~~~~~~ ^~ ~~~
      |           |              |
      |           |              const char [2]
      |           std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/iostream:42,
                 from a.cc:1:
/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:12:26: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'const char*'
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
/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:12:26: error: invalid conversion from 'const char*' to 'short int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(short int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const char*' to 'short unsigned int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(short unsigned int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const char*' to 'int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const char*' to 'unsigned int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(unsigned int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const char*' to 'long int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(long int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const char*' to 'long unsigned int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(long unsigned int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const char*' to 'long long int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(long long int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const char*' to 'long long unsigned int' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const char*
a.cc:12:26: error: cannot bind rvalue '(long long unsigned int)((const char*)" ")' 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:12:26: error: invalid conversion from 'const void*' to 'void*' [-fpermissive]
   12 |       cin >> data1[x] >> " " >> data2[x];
      |                          ^~~
      |                          |
      |                          const void*
a.cc:12:26: error: cannot bind rvalue '(void*)((const void*)((const char*)" "))' to 'void*&'
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:25: note:   no known conversion for argument 1 from 'const char [2]' to 'float&'
  219 |       operator>>(float& __f)
      |                  ~~~~~~~^~~
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:26: note:   no known conversion for argument 1 from 'const char [2]' to 'double&'
  223 |       operator>>(double& __f)
      |                  ~~~~~~~~^~~
/usr/include/c++/14/istream:227:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:31: note:   no known conversion for argument 1 from 'const char [2]' to 'long double&'
  227 |       operator>>(long double& __f)
      |                  ~~~~~~~~~~~~~^~~
/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>]'
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:36: note:   no known conversion for argument 1 from 'const char [2]' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::