Language: C++

#include<iostream>
#include<iomanip>
#include<limits>
#include<string>
#include<vector>
#include<algorithm>
#include<stdio.h>
#include<cmath>


using namespace std;

typedef unsigned long long ull;
typedef long long ll;

#define big ((ll)(1e9)+7)


int main()
{
  int n,m;
  cin >> n >> m;
  vector<int> s;
  vector<int> c;
  if(m == 0)
  {
    cout << 0 << endl;
    return 0;
  }
  for(int i = 0;i < m;i++)
  {
    int S,C;
    cin >> S >> C;
    s.push_back(S);
    c.push_back(C);
  }
  // if(m == 1)
  // {
  //   if(c[0] == 0)
  //   {
  //     cout << -1 << endl;
  //     return 0;
  //   }
  // }
  int a = 10;
  bool a_f = false;
  int b = 10;
  bool b_f = false;
  int d = 10;
  bool d_f = false;
  bool flag = false;
  if(n == 1)
  {
    for(int i = 0;i < m;i++)
    {
      if(s[i] == 1 && d_f != true)
      {
        // cout << d << endl;
        d = min(d,c[i]);
        d_f = true;
        // if(d == 0)
        //   flag = true;
        // cout << d << endl;
      }
      else if(s[i] == 1 && d_f && d != c[i])
      {
        cout << -1 << endl;
        return 0;
      }
    }
    if(d == 10)
    {
      cout << -1 << endl;
      return 0;
    }
    cout << d << endl;
    return 0;
  }
  else if(n == 2)
  {
    for(int i = 0;i < m;i++)
    {
      if(s[i] == 1 && b_f != true)
      {
        b = min(b,c[i]);
        b_f = true;
      }
      else if(s[i] == 1 && b_f && b != c[i])
      {
        cout << -1 << endl;
        return 0;
      }
      else if(s[i] == 2 && d_f != true)
      {
        // cout << d << endl;
        d = min(d,c[i]);
        d_f = true;
        if(d == 0)
        flag = true;
        // cout << d << endl;
      }
      else if(s[i] == 2 && d_f && d != c[i])
      {
        cout << -1 << endl;
        return 0;
      }
    }
    if( b == 0 && c == 0)
    {
      cout << 0 << endl;
      return 0;
    }
    if(b == 10)
      b = 0;
    if(d == 10)
      d = 0;
    if(b == 0 && d == 0)
    {
      // if(flag)
      // {
      //   cout << d << endl;
      //   return 0;
      // }
      cout << -1 << endl;
      return 0;
    }
    else if(b == 0 && d != 0)
    {
      cout << d << endl;
    }
    else
    {
      cout << b << d << endl;
    }
    return 0;
  }
  else if(n == 3)
  {
    for(int i = 0;i < m;i++)
    {
      // cout << i <<"?" << endl;
      if(s[i] == 1 && a_f != true)
      {
        a = min(a,c[i]);
        a_f = true;
      }
      else if(s[i] == 1 && a_f && a != c[i])
      {
        cout << -1 <<endl;
        return 0;
      }
      else if(s[i] == 2 && b_f != true)
      {
        b = min(b,c[i]);
        b_f = true;
      }
      else if(s[i] == 2 && b_f && b != c[i])
      {
        cout << -1 << endl;
        return 0;
      }
      else if(s[i] == 3 && d_f != true)
      {
        // cout << d << endl;
        d = min(d,c[i]);
        d_f = true;
        if(d == 0)
        flag = true;
        // cout << d << endl;
      }
      else if(s[i] == 3 && d_f && d != c[i])
      {
        cout << -1 << endl;
        return 0;
      }
    }
    if(a == 0 && b == 0 && c == 0)
    {
      cout << 0 << endl;
      return 0;
    }
    if(a == 10)
      a = 0;
    if(b == 10)
      b = 0;
    if(d == 10)
      d = 0;
    if(a == 0 && b == 0 && d == 0)
    {
      // if(flag)
      // {
      //   cout << d << endl;
      //   return 0;
      // }
      cout << -1 << endl;
      return 0;
    }
    else if(a == 0 && b != 0 && d != 0)
    {
      cout << b << d << endl;
    }
    else if(a == 0 && b != 0 && d == 0)
    {
      cout << b << d << endl;
    }
    else if(a == 0 && b == 0 && d != 0)
    {
      cout << d << endl;
    }
    else
    {
      cout << a << b << d << endl;
    }
  }
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:108:21: error: no match for 'operator==' (operand types are 'std::vector<int>' and 'int')
  108 |     if( b == 0 && c == 0)
      |                   ~ ^~ ~
      |                   |    |
      |                   |    int
      |                   std::vector<int>
In file included from /usr/include/c++/14/iosfwd:42,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/postypes.h:192:5: note: candidate: 'template<class _StateT> bool std::operator==(const fpos<_StateT>&, const fpos<_StateT>&)'
  192 |     operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:192:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::fpos<_StateT>'
  108 |     if( b == 0 && c == 0)
      |                        ^
In file included from /usr/include/c++/14/string:43,
                 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:
/usr/include/c++/14/bits/allocator.h:235:5: note: candidate: 'template<class _T1, class _T2> bool std::operator==(const allocator<_CharT>&, const allocator<_T2>&)'
  235 |     operator==(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:235:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::allocator<_CharT>'
  108 |     if( b == 0 && c == 0)
      |                        ^
In file included from /usr/include/c++/14/string:48:
/usr/include/c++/14/bits/stl_iterator.h:441:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  441 |     operator==(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:441:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::reverse_iterator<_Iterator>'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/bits/stl_iterator.h:486:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  486 |     operator==(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::reverse_iterator<_Iterator>'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1667 |     operator==(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::move_iterator<_IteratorL>'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1737 |     operator==(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::move_iterator<_IteratorL>'
  108 |     if( b == 0 && c == 0)
      |                        ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1033:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator==(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1033 |     operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1033:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::pair<_T1, _T2>'
  108 |     if( b == 0 && c == 0)
      |                        ^
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:629:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  629 |     operator==(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:629:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/string_view:637:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  637 |     operator==(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:637:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/string_view:644:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  644 |     operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:644:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'int'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/bits/basic_string.h:3755:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3755 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3755:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/bits/basic_string.h:3772:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3772 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3772:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
  108 |     if( b == 0 && c == 0)
      |                        ^
/usr/include/c++/14/bits/basic_string.h:3819:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3819 |     operator==(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3819:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   mismatched types 'const _CharT*' and 'std::vector<int>'
  108 |     if( b == 0 && c == 0)
      |                        ^
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/tuple:2558:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2558 |     operator==(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2558:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::tuple<_UTypes ...>'
  108 |     if( b == 0 && c == 0)
      |                        ^
In file included from /usr/include/c++/14/bits/locale_facets.h:48,
                 from /usr/include/c++/14/bits/basic_ios.h:37,
                 from /usr/include/c++/14/ios:46:
/usr/include/c++/14/bits/streambuf_iterator.h:234:5: note: candidate: 'template<class _CharT, class _Traits> bool std::operator==(const istreambuf_iterator<_CharT, _Traits>&, const istreambuf_iterator<_CharT, _Traits>&)'
  234 |     operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
      |     ^~~~~~~~
/usr/include/c++/14/bits/streambuf_iterator.h:234:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   'std::vector<int>' is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
  108 |     if( b == 0 && c == 0)
      |                        ^
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:5:
/usr/include/c++/14/bits/stl_vector.h:2050:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator==(const vector<_Tp, _Alloc>&, const vector<_Tp, _Alloc>&)'
 2050 |     operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:2050:5: note:   template argument deduction/substitution failed:
a.cc:108:24: note:   mismatc