Language: C++

#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
#define endl "\n"
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define prt(x) cout << (x)
#define prtl(x) cout << (x) << endl
#define rep(i,a,b) for(ll i=a; i<b; i++)
#define rrep(i,a,b) for(ll i=a; i>b; i--)
#define mp(a, b) make_pair(a, b)
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
using namespace std;
using vi = vector<int>;
using vll = vector<long long int>;
using vb = vector<bool>;
using vvb = vector<vector<bool>>;
using vc = vector<char>;
using vvi = vector<vector<int>>;
using vvll = vector<vector<long long int>>;
using vvc = vector<vector<char>>;
using ll = long long int;
using P = pair<long long int, long long int>;
using Map = map<long long int, long long int>;
ll INF = 1LL<<60;
ll M = 1000000007;


int main(){
    ll N; cin >> N;
    string S; cin >> S;
    ll Q; cin >> Q;
    set<ll> sg[26];
    rep(i, 0, N){
        ll d = S[i] - 'a';
        sg[d].insert(i);
    }
    rep(i, 0, Q){
        ll a; cin >> a;
        if(a == 1){
            ll x; char q;
            cin >> x >> q;
            if(q == S[x-1]){
                continue;
            }
            ll e = S[x-1] - 'a', f = q - 'a';
            sg[e].erase(x-1); sg[f].insert(x-1);
        }else{
            ll l, r; cin >> l >> r;
            l--; r--;
            ll c = 0;
            rep(j, 0, 26){
                ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
                ll n = upper_bound(all(sg[j]), r) - sg[j].begin();
                if(m != n){
                    c++;
                }
            }
            prtl(c);
        }
    }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:53:53: error: no match for 'operator-' (operand types are 'std::_Rb_tree_const_iterator<long long int>' and 'std::set<long long int>::iterator' {aka 'std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, std::less<long long int>, std::allocator<long long int> >::const_iterator'})
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~
      |                                   |                              |
      |                                   _Rb_tree_const_iterator<[...]> _Rb_tree_const_iterator<[...]>
In file included from /usr/include/c++/14/bits/stl_algobase.h:67,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:2:
/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:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::reverse_iterator<_Iterator>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/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:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::move_iterator<_IteratorL>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/complex:370:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&, const complex<_Tp>&)'
  370 |     operator-(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:370:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::complex<_Tp>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/complex:379:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&, const _Tp&)'
  379 |     operator-(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:379:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::complex<_Tp>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/complex:388:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const _Tp&, const complex<_Tp>&)'
  388 |     operator-(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:388:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::set<long long int>::iterator' {aka 'std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, std::less<long long int>, std::allocator<long long int> >::const_iterator'} is not derived from 'const std::complex<_Tp>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/complex:465:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator-(const complex<_Tp>&)'
  465 |     operator-(const complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/include/c++/14/complex:465:5: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166:
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::set<long long int>::iterator' {aka 'std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, std::less<long long int>, std::allocator<long long int> >::const_iterator'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/bits/valarray_after.h:406:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__minus, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__minus, typename _Dom1::value_type>::result_type> std::operator-(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  406 |     _DEFINE_EXPR_BINARY_OPERATOR(-, struct std::__minus)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:406:5: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::set<long long int>::iterator' {aka 'std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, std::less<long long int>, std::allocator<long long int> >::const_iterator'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/valarray:1197:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__minus, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__minus, _Tp>::result_type> std::operator-(const valarray<_Tp>&, const valarray<_Tp>&)'
 1197 | _DEFINE_BINARY_OPERATOR(-, __minus)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1197:1: note:   template argument deduction/substitution failed:
a.cc:53:67: note:   'std::_Rb_tree_const_iterator<long long int>' is not derived from 'const std::valarray<_Tp>'
   53 |                 ll m = upper_bound(all(sg[j]), l-1) - sg[j].begin();
      |                                                                   ^
/usr/include/c++/14/valarray:1197:1