Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  int N, M;
  cin >> N >> M;
  vector<int> S, C;
  for (int i = 0; i < M; i++) {
    int s, c;
    cin >> s >> c;
    S.at(i) = s;
    C.at(i) = c;
  }
  vector<vector<int>> digit(N);
  for (int i = 0; i < M; i++) {
    digit.at(S.at(i) - 1).push_back(C.at(i))
  }
  bool exceed = false;
  for (int i = 0; i < N; i++) {
    if (digit.at(i).size() > 1) {
      set<int> = SET
      for (int j = 0; j < digit.at(i).size(); j++) {
        SET.insert(digit.at(i).at(j));
      }
      if (SET.size() > 1) {
        exceed = true;
      }
    }
  }
  if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
    cout << -1 << endl;
    return 0;
  }
  vector<int> nums = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
  int ans = 0;
  for (int i = 0; i < N; i++) {
    if (!digit.at(i).empty())
      ans += nums.at(digit.at(i).at(0)) * pow(10, N - i - 1);
  }
  cout << ans << endl;
}
  

Compiler output:
a.cc: In function 'int main()':
a.cc:16:45: error: expected ';' before '}' token
   16 |     digit.at(S.at(i) - 1).push_back(C.at(i))
      |                                             ^
      |                                             ;
   17 |   }
      |   ~                                          
a.cc:21:16: error: expected unqualified-id before '=' token
   21 |       set<int> = SET
      |                ^
a.cc:22:23: error: 'j' was not declared in this scope
   22 |       for (int j = 0; j < digit.at(i).size(); j++) {
      |                       ^
a.cc:25:11: error: 'SET' was not declared in this scope
   25 |       if (SET.size() > 1) {
      |           ^~~
a.cc:30:34: error: no match for 'operator==' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} and 'int')
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                  ~~~~~~~~~~~~~~~ ^~ ~
      |                          |          |
      |                          |          int
      |                          __gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type {aka std::vector<int>}
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181,
                 from a.cc:1:
/usr/include/c++/14/bits/regex.h:1103:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1103 |     operator==(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1103:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/usr/include/c++/14/bits/regex.h:1199:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator==(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1199 |     operator==(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1199:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/usr/include/c++/14/bits/regex.h:1274:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator==(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1274 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1274:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/usr/include/c++/14/bits/regex.h:1366:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1366 |     operator==(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1366:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/usr/include/c++/14/bits/regex.h:1441:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1441 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1441:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/usr/include/c++/14/bits/regex.h:1534:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1534 |     operator==(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1534:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/usr/include/c++/14/bits/regex.h:1613:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1613 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1613:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/usr/include/c++/14/bits/regex.h:2186:5: note: candidate: 'template<class _Bi_iter, class _Alloc> bool std::__cxx11::operator==(const match_results<_BiIter, _Alloc>&, const match_results<_BiIter, _Alloc>&)'
 2186 |     operator==(const match_results<_Bi_iter, _Alloc>& __m1,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:2186:5: note:   template argument deduction/substitution failed:
a.cc:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h: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:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::pair<_T1, _T2>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/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:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/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:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/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:30:37: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::move_iterator<_IteratorL>'
   30 |   if (exceed || (digit.at(N - 1) == 0 && N != 1)) {
      |                                     ^
/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:30:37: note