Submission #379781

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
379781	2021-03-19T09:30:48 Z	Jarif_Rahman	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	Compilation error	0 ms	0 KB

joitter2

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
struct dsu{
    int n;
    vector<int> p;
    vector<ll> sz;
    vector<set<int>> aa, bb;
    vector<set<pair<int, int>>> cnt;
    vector<ll> cnt2;
    ll ans;
    dsu(int nn){
        n = nn;
        ans = 0;
        sz.resize(n, 1);
        p.resize(n);
        aa.resize(n);
        bb.resize(n);
        cnt.resize(n);
        cnt2.resize(n);
        for(int i = 0; i < n; i++) p[i] = i;
    }
    int get(int x){
        if(p[x] != x) p[x] = get(p[x]);
        return p[x];
    }
    void unite(int a, int b){
        a = get(a), b  = get(b);
        if(a == b) return;
        if(sz[b] > sz[a]) swap(a, b);
        ans-=sz[a]*(sz[a]-1);
        ans-=cnt2[a]*sz[a];
        ans-=sz[b]*(sz[b]-1);
        ans-=cnt2[b]*sz[b];
 
 
        auto it = cnt[a].lower_bound({b, 0});
        if(it < cnt[a].end() && (*it).f == b){
            cnt2[a]-=(*it).sc;
            cnt[a].erase(it);
        }
        it = cnt[b].lower_bound({a, 0});
        if(it != cnt[b].end() && (*it).f == a){
            cnt2[a]-=(*it).sc;
            cnt[b].erase(it);
        }
        
        aa[a].erase(b);
        bb[a].erase(b);
        aa[b].erase(a);
        bb[b].erase(a);
 
        auto exc = [&](int x, int y, int a0, int b0){
            auto it = cnt[b0].lower_bound({x, 0});
            if(it == cnt[b0].end() || (*it).f != x) return;
            auto p = (*it);
            p.f = y;
            cnt[b0].erase(it);
            it = cnt[a0].lower_bound({y, 0});
            if(it == cnt[a0].end() || (*it).f != y){
                cnt[a0].insert(p);
            }
            else{
                p.sc+=(*it).sc;
                cnt[a0].erase(it);
                cnt[a0].insert(p);
            }
        };
 
        while(!aa[b].empty()){
            int x = *aa[b].begin();
            aa[b].erase(aa[b].begin());
            exc(x, x, a, b);
            bb[x].erase(b);
            bb[x].insert(a);
            aa[a].insert(x);
        }
        while(!bb[b].empty()){
            int x = *bb[b].begin();
            bb[b].erase(bb[b].begin());
            exc(a, b, x, x);
            aa[x].erase(b);
            aa[x].insert(a);
            bb[a].insert(x);
        }
 
        sz[a]+=sz[b];
        sz[b] = 0;
        p[b] = a;
        cnt2[a] = bb[a].size();
        ans+=cnt2[a]*sz[a];
        ans+=sz[a]*(sz[a]-1);
 
        for(int x: aa[a]) if(bb[a].find(x) != bb[a].end()) unite(a, x);
    }
    void add_edge(int a, int b){
        a = get(a), b = get(b);
        if(a == b) return;
        if(aa[a].find(b) != aa[a].end()) return;
        aa[a].insert(b);
        bb[b].insert(a);
        ans+=sz[b];
        auto it = cnt[a].lower_bound({b, 0});
        cnt2[b]++;
        if(it == cnt[a].end() || (*it).f != b){
            cnt[a].insert({b, 1});
        }
        else{
            auto p = *it;
            p.sc++;
            cnt[a].erase(it);
            cnt[a].insert(p);
        }
        if(aa[b].find(a) != aa[b].end()) unite(a, b);
    }
};
 
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m; cin >> n >> m;
    dsu ds(n);
    for(int i = 0; i < m; i++){
        int a, b; cin >> a >> b; a--, b--;
        ds.add_edge(a, b);
        cout << ds.ans << "\n";
    }
}

Compilation message

joitter2.cpp: In member function 'void dsu::unite(int, int)':
joitter2.cpp:42:15: error: no match for 'operator<' (operand types are 'std::_Rb_tree_const_iterator<std::pair<int, int> >' and 'std::set<std::pair<int, int> >::iterator' {aka 'std::_Rb_tree_const_iterator<std::pair<int, int> >'})
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |            ~~ ^ ~~~~~~~~~~~~
      |            |              |
      |            |              _Rb_tree_const_iterator<[...]>
      |            _Rb_tree_const_iterator<[...]>
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/regex.h:1048:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const std::__cxx11::sub_match<_BiIter>&)'
 1048 |     operator<(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1048:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/regex.h:1124:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const std::__cxx11::sub_match<_BiIter>&)'
 1124 |     operator<(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1124:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/regex.h:1198:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1198 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1198:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/regex.h:1272:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type*, const std::__cxx11::sub_match<_BiIter>&)'
 1272 |     operator<(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1272:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::set<std::pair<int, int> >::iterator' {aka 'std::_Rb_tree_const_iterator<std::pair<int, int> >'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/regex.h:1346:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1346 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1346:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/regex.h:1421:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type&, const std::__cxx11::sub_match<_BiIter>&)'
 1421 |     operator<(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1421:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::set<std::pair<int, int> >::iterator' {aka 'std::_Rb_tree_const_iterator<std::pair<int, int> >'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/regex.h:1499:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1499 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1499:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/stl_algobase.h:64,
                 from /usr/include/c++/9/bits/specfun.h:45,
                 from /usr/include/c++/9/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/stl_pair.h:454:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)'
  454 |     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_pair.h:454:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::pair<_T1, _T2>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 from /usr/include/c++/9/bits/specfun.h:45,
                 from /usr/include/c++/9/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/stl_iterator.h:331:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)'
  331 |     operator<(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:331:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 from /usr/include/c++/9/bits/specfun.h:45,
                 from /usr/include/c++/9/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/stl_iterator.h:369:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)'
  369 |     operator<(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:369:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 from /usr/include/c++/9/bits/specfun.h:45,
                 from /usr/include/c++/9/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/stl_iterator.h:1163:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)'
 1163 |     operator<(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:1163:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::move_iterator<_IteratorL>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 from /usr/include/c++/9/bits/specfun.h:45,
                 from /usr/include/c++/9/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/stl_iterator.h:1169:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)'
 1169 |     operator<(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:1169:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::move_iterator<_IteratorL>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/basic_string.h:48,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from joitter2.cpp:1:
/usr/include/c++/9/string_view:509:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(std::basic_string_view<_CharT, _Traits>, std::basic_string_view<_CharT, _Traits>)'
  509 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/9/string_view:509:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/basic_string.h:48,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from joitter2.cpp:1:
/usr/include/c++/9/string_view:515:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(std::basic_string_view<_CharT, _Traits>, std::__detail::__idt<std::basic_string_view<_CharT, _Traits> >)'
  515 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/9/string_view:515:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/basic_string.h:48,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from joitter2.cpp:1:
/usr/include/c++/9/string_view:521:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(std::__detail::__idt<std::basic_string_view<_CharT, _Traits> >, std::basic_string_view<_CharT, _Traits>)'
  521 |     operator< (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/9/string_view:521:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6226:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 6226 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6226:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6239:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 6239 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6239:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   'std::_Rb_tree_const_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from joitter2.cpp:1:
/usr/include/c++/9/bits/basic_string.h:6251:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 6251 |     operator<(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6251:5: note:   template argument deduction/substitution failed:
joitter2.cpp:42:28: note:   mismatched types 'const _CharT*' and 'std::_Rb_tree_const_iterator<std::pair<int, int> >'
   42 |         if(it < cnt[a].end() && (*it).f == b){
      |                            ^
In file included from /usr/include/c++/9/bits/ios_base.h:46,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from joitter2.cpp:1:
/usr/include/c++/9/system_error:208:3: note: candidate: 'bool std::operator<(const std::error_code&,