Language: C++

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
#include <cmath>
#include <bitset>
#include <iomanip>
#include <stack>
#include <list>
#include <map>
#include <unordered_map>
#include <chrono>
#include <numeric>
using namespace std;
using ll = long long;
const long long INF = (long long)1e18+1;
#define DIV 1000000007

bool compare_by_pair(pair<long,long> a, pair<long,long> b) {
    if(a.second != b.second){
        return a.second < b.second;
    }
    return a.second == b.second;
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
#ifdef TEST
    chrono::system_clock::time_point start, end;
    start = chrono::system_clock::now();
#endif
    long idx=0;
    long N;
    cin >> N;
    long a;
    vector<pair<long, long>> A(N);
    for(size_t i=1;i<=N; i++)
    {
        //出席番号 i の出席したときの教室の人数 A[i]
        cin >> a;
        A[i-1] = tie(i, a);
    }
    sort(A.begin(), A.end(), compare_by_pair);
    for(size_t i=0;i<N; i++)
    {
        cout << A[i].first << " ";
    }
    cout << endl;
#ifdef TEST
    end = chrono::system_clock::now();
    cerr << static_cast<double>(chrono::duration_cast<chrono::microseconds>(end - start).count() / 1000.0) << "[ms]" << endl;
#endif
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:43:26: error: no match for 'operator=' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} and 'std::tuple<long unsigned int&, long int&>')
   43 |         A[i-1] = tie(i, a);
      |                          ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51,
                 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/bits/stl_pair.h:946:9: note: candidate: 'template<class _U1, class _U2> typename std::enable_if<std::__and_<std::is_assignable<_T1&, const _U1&>, std::is_assignable<_T2&, const _U2&> >::value, std::pair<_T1, _T2>&>::type std::pair<_T1, _T2>::operator=(const std::pair<_U1, _U2>&) [with _U2 = _U1; _T1 = long int; _T2 = long int]'
  946 |         operator=(const pair<_U1, _U2>& __p)
      |         ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:946:9: note:   template argument deduction/substitution failed:
a.cc:43:26: note:   'std::tuple<long unsigned int&, long int&>' is not derived from 'const std::pair<_T1, _T2>'
   43 |         A[i-1] = tie(i, a);
      |                          ^
/usr/include/c++/14/bits/stl_pair.h:957:9: note: candidate: 'template<class _U1, class _U2> typename std::enable_if<std::__and_<std::is_assignable<_T1&, _U1&&>, std::is_assignable<_T2&, _U2&&> >::value, std::pair<_T1, _T2>&>::type std::pair<_T1, _T2>::operator=(std::pair<_U1, _U2>&&) [with _U2 = _U1; _T1 = long int; _T2 = long int]'
  957 |         operator=(pair<_U1, _U2>&& __p)
      |         ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:957:9: note:   template argument deduction/substitution failed:
a.cc:43:26: note:   'std::tuple<long unsigned int&, long int&>' is not derived from 'std::pair<_T1, _T2>'
   43 |         A[i-1] = tie(i, a);
      |                          ^
/usr/include/c++/14/bits/stl_pair.h:921:7: note: candidate: 'std::pair<_T1, _T2>& std::pair<_T1, _T2>::operator=(std::__conditional_t<((bool)std::__and_<std::is_copy_assignable<_T1>, std::is_copy_assignable<_T2> >::value), const std::pair<_T1, _T2>&, const std::__nonesuch&>) [with _T1 = long int; _T2 = long int; std::__conditional_t<((bool)std::__and_<std::is_copy_assignable<_T1>, std::is_copy_assignable<_T2> >::value), const std::pair<_T1, _T2>&, const std::__nonesuch&> = const std::pair<long int, long int>&]'
  921 |       operator=(__conditional_t<__and_<is_copy_assignable<_T1>,
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:923:65: note:   no known conversion for argument 1 from 'std::tuple<long unsigned int&, long int&>' to 'std::__conditional_t<true, const std::pair<long int, long int>&, const std::__nonesuch&>' {aka 'const std::pair<long int, long int>&'}
  921 |       operator=(__conditional_t<__and_<is_copy_assignable<_T1>,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  922 |                                        is_copy_assignable<_T2>>::value,
      |                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  923 |                                 const pair&, const __nonesuch&> __p)
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_pair.h:931:7: note: candidate: 'std::pair<_T1, _T2>& std::pair<_T1, _T2>::operator=(std::__conditional_t<((bool)std::__and_<std::is_move_assignable<_Tp>, std::is_move_assignable<_T2> >::value), std::pair<_T1, _T2>&&, std::__nonesuch&&>) [with _T1 = long int; _T2 = long int; std::__conditional_t<((bool)std::__and_<std::is_move_assignable<_Tp>, std::is_move_assignable<_T2> >::value), std::pair<_T1, _T2>&&, std::__nonesuch&&> = std::pair<long int, long int>&&]'
  931 |       operator=(__conditional_t<__and_<is_move_assignable<_T1>,
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:933:55: note:   no known conversion for argument 1 from 'std::tuple<long unsigned int&, long int&>' to 'std::__conditional_t<true, std::pair<long int, long int>&&, std::__nonesuch&&>' {aka 'std::pair<long int, long int>&&'}
  931 |       operator=(__conditional_t<__and_<is_move_assignable<_T1>,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  932 |                                        is_move_assignable<_T2>>::value,
      |                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  933 |                                 pair&&, __nonesuch&&> __p)
      |                                 ~~~~~~~~~~~~~~~~~~~~~~^~~