Language: C++

#include <iostream>
#include <string>
#include <cstdlib>
#include <vector>
#include <array>
#include <map>
#include <set>
#include <algorithm>
#include <queue>
#include <stack>
#define _USE_MATH_DEFINES
#include <cmath>
#include <climits>
#include <cstdio>
#include <iomanip>
#include <utility>
#include <unordered_map>

using namespace std;
typedef long long int ll;

#define SP(x) setprecision((int)x)
#define ALL(v) v.begin(), v.end()

int main(int argc, char const *argv[])
{
    string s, t;
    cin >> s >> t;
    set<string> ss;
    for (ll i = 0; i < s.size() - t.size() + 1; i++)
    {
        string temp = s;
        for (ll k = 0; k < t.size(); k++)
        {
            if (temp[i + k] == t[k])
            {
            }
            else
            {
                if (temp[i + k] == '?')
                    temp[i + k] = t[k];
                else
                {
                    break;
                }
            }
            if (k == t.size() - 1)
            {
                for (ll m = 0; m < temp.size(); m++)
                {
                    if (temp[m] == '?')
                        temp[m] = 'a';
                }
                ss.insert(temp);
            }
        }
    }
    if (ss.empty())
    {
        cout << "UNRESTOREBLE" << endl;
    }
    else
    {
        sort(ALL(ss));
        cout << *ss.begin() << endl;
    }
}


Compiler output:
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:8:
/usr/include/c++/14/bits/stl_algo.h: In instantiation of 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = _Rb_tree_const_iterator<__cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]':
/usr/include/c++/14/bits/stl_algo.h:4772:18:   required from 'void std::sort(_RAIter, _RAIter) [with _RAIter = _Rb_tree_const_iterator<__cxx11::basic_string<char> >]'
 4772 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_less_iter());
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:64:13:   required from here
   64 |         sort(ALL(ss));
      |         ~~~~^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1906:50: error: no match for 'operator-' (operand types are 'std::_Rb_tree_const_iterator<std::__cxx11::basic_string<char> >' and 'std::_Rb_tree_const_iterator<std::__cxx11::basic_string<char> >')
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                           ~~~~~~~^~~~~~~~~
In file included from /usr/include/c++/14/string:48,
                 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_iterator.h:618:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr decltype ((__y.base() - __x.base())) std::operator-(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  618 |     operator-(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:618:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_algo.h:1906:50: note:   'std::_Rb_tree_const_iterator<std::__cxx11::basic_string<char> >' is not derived from 'const std::reverse_iterator<_Iterator>'
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                           ~~~~~~~^~~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1790:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr decltype ((__x.base() - __y.base())) std::operator-(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1790 |     operator-(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1790:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_algo.h:1906:50: note:   'std::_Rb_tree_const_iterator<std::__cxx11::basic_string<char> >' is not derived from 'const std::move_iterator<_IteratorL>'
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                           ~~~~~~~^~~~~~~~~