Language: C++

#include <iostream>
#include <utility>
#include <cmath>
using namespace std;
bool check(int* cube){
    for(int i = 1; i < 9; i++){
        if(cube[i] != cube[0]){
            return false;
        }
    }
    for(int i = 10; i < 12; i++){
        if(cube[i] != cube[9] || cube[i + 3] != cube[12]){
            return false;
        }
    }
    return true;
}

void turn(int* cube, int i){
    switch(i){
        case 0:
        for(int i = 0; i <= 6; i += 3){
            swap(cube[i], cube[23 + i]);
        }
        swap(cube[20], cube[9]);
        swap(cube[15], cube[17]);
        break;
        
        case 1:
        for(int i = 0; i < 3; i++){
            swap(cube[i], cube[27 + i]);
        }
        swap(cube[14], cube[15]);
        swap(cube[20], cube[18]);
        break;
        
        case 2:
        for(int i = 2; i <= 8; i += 3){
            swap(cube[i], cube[19 + i]);
        }
        swap(cube[18], cube[11]);
        swap(cube[14], cube[12]);
        break;
        
        case 3:
        for(int i = 6; i <= 8; i++){
            swap(cube[i], cube[15 + i]);
        }
        swap(cube[17], cube[12]);
        swap(cube[9], cube[11]);
        break;
        default:break;
    }
}

int minimumTurn = 9;

void calc(int* cube, int currentTurnCount, int prevTurn){
    currentTurnCount++;
    if(currentTurnCount >= minimumTurn){
        return;
    }
    for(int i = 0; i < 4; i++){
        if(i == prevTurn){
            continue;
        }
        int tempCube[30];
        for(int j = 0; j < 30; j++){
            tempCube[j] = cube[j];
        }
        turn(cube, i);
        if(check(cube)){
            minimumTurn = min(minimumTurn, currentTurnCount);
            return;
        }
        calc(cube, currentTurnCount, i);
        for(int j = 0; j < 30; j++){
            cube[j] = tempCube[j];
        }
    }
}

int main(){

    int n = 1;
    cin << n;
    for(int k = 0; k < n; k++){
        int cube[30];
        for(int i = 0; i < 30; i++){
            cin >> cube[i];
        }
        minimumTurn = 9;
        if(!check(cube)){
            calc(cube, 0, -1);
        }else{
            minimumTurn = 0;
        }
        cout << minimumTurn << endl;
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:86:9: error: no match for 'operator<<' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'int')
   86 |     cin << n;
      |     ~~~ ^~ ~
      |     |      |
      |     |      int
      |     std::istream {aka std::basic_istream<char>}
a.cc:86:9: note: candidate: 'operator<<(int, int)' (built-in)
   86 |     cin << n;
      |     ~~~~^~~~
a.cc:86:9: note:   no known conversion for argument 1 from 'std::istream' {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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   86 |     cin << n;
      |            ^
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:86:5: note:   cannot convert 'std::cin' (type 'std::istream' {aka 'std::basic_istream<char>'}) to type 'std::byte'
   86 |     cin << n;
      |     ^~~
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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   86 |     cin << n;
      |            ^
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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   86 |     cin << n;
      |            ^
/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:86:12: note:   'std::istream' {aka 'std::basic_istream<char>'} is not derived from 'std::basic_ostream<char, _Traits>'
   86 |     cin << n;
      |            ^
/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 'template<class _Ostream, class _Tp> _Ostream&& std::operator<<(_Ostream&&, const _Tp&) [with _Ostream = std::basic_istream<char>&; _Tp = int]':
a.cc:86:12:   required from here
   86 |     cin << n;
      |            ^
/usr/include/c++/14/ostream:810:5: error: no type named 'type' in 'struct std::enable_if<false, void>'
  810 |     operator<<(_Ostream&& __os, const _Tp& __x)
      |     ^~~~~~~~