oj.uz

Submission #1051838

# Submission time Handle Problem Language Result Execution time Memory
1051838 2024-08-10T10:07:02 Z Ludissey Regions (IOI09_regions) C++17
Compilation error
 0 ms 0 KB 
#include <bits/stdc++.h>
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;

typedef
tree<
  int,
  null_type,
  less<int>,
  rb_tree_tag,
  tree_order_statistics_node_update>
ordered_set;

vector<vector<int>> child;
vector<int> parent;
vector<vector<pair<int,int>>> up;
unordered_map<int,int> conv;
vector<int> rg;
vector<vector<int>> pr;
int need;
int sq;
vector<int> tin;
vector<int> out;
int timer=0;


vector<int> setup_down(int x, vector<int> rm){
    vector<int> cv(sq);
    if(conv[rg[x]]<sq){
        up[conv[rg[x]]][conv[rg[x]]].second++;
        cv[conv[rg[x]]]++;
        up[conv[rg[x]]][conv[rg[x]]].first++;
        rm[conv[rg[x]]]++;
    }
    for (int i=0; i<sz(rm); i++)
    {
        up[conv[rg[x]]][i].first+=rm[i];
    }
    for (auto u : child[x]) {
        vector<int> v=setup_down(u,rm);
        for (int i=0; i<sq; i++)
        {
            up[conv[rg[x]]][i].second+=v[i];
            cv[i]+=v[i];
        }
    }
    return cv;
}


void setup_euler(int x){
    tin[x]=timer++;
    for (auto u : child[x]) setup_euler(u);
    out[x]=timer++;
}

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    int N,R,Q; cin >> N >> R >> Q;
    child.resize(N);
    parent.resize(N);
    up.resize(R,vector<pair<int,int>>(sq));
    rg.resize(N);
    tin.resize(N);
    out.resize(N);
    pr.resize(R);
    cin >> rg[0]; rg[0]--;
    vector<pair<int,int>> cnt(R);
    pr[rg[0]].push_back(0);
    cnt[rg[0]].first++;
    for (int i = 1; i < N; i++)
    {
        cin >> parent[i] >> rg[i]; parent[i]--; rg[i]--;
        child[parent[i]].push_back(i);
        pr[rg[i]].push_back(i);
        cnt[rg[i]].first++;
    }
    for (int i = 0; i < R; i++) cnt[i].second=i;
    
    sort(all(cnt),[&](auto &aa, auto &bb){return aa>bb; });
    for (int i = 0; i < sz(cnt); i++)
    {
        conv[cnt[i].second]=i;
    }
    sq=upper_bound(all(conv), sqrt(N));
    vector<int> ep(sq);
    timer=0;
    setup_euler(0);
    timer++;
    setup_down(0,ep);
    for (int i = 0; i < Q; i++)
    {
        int sm=0;
        int e1,e2; cin >> e1>>e2; e1--; e2--;
        if(conv[e1]<sq){
            sm=up[conv[e2]][conv[e1]].first;
        }else if(conv[e2]<sq) {
            sm=up[conv[e1]][conv[e2]].second;
        }else{
            vector<pair<int,pair<int,int>>> tos;
            for (int j = 0; j < sz(pr[e1]); j++) {
                int in1=tin[pr[e1][j]], out1=out[pr[e1][j]];
                tos.push_back({in1,{out1,1}});
            }   
            for (int j = 0; j < sz(pr[e2]); j++)
            {
                int in1=tin[pr[e2][j]], out1=out[pr[e2][j]];
                tos.push_back({in1,{out1,2}});

            }
            sort(all(tos));
            ordered_set st;
            int ones=0;
            for (int j = 0; j < sz(tos); j++)
            {
                if(tos[j].second.second==1) {
                    ones++;
                    int p=tos[j].second.first;
                    st.insert(p);
                    //cerr << "add " << p << "\n";
                }
                else{
                    int r=tos[j].second.first;
                    int csum=st.order_of_key(r);
                    sm+=ones-csum;
                    //cerr << "query " << r <<" for " << csum << " " << ones <<  "\n";

                }
            }
        }
        cout << sm << endl;
    }
    
    return 0;
}

Compilation message

regions.cpp: In function 'int main()':
regions.cpp:89:19: error: cannot convert 'std::__detail::_Node_iterator<std::pair<const int, int>, false, false>' to 'int' in assignment
   89 |     sq=upper_bound(all(conv), sqrt(N));
      |        ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
      |                   |
      |                   std::__detail::_Node_iterator<std::pair<const int, int>, false, false>
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Val_less_iter::operator()(_Value&, _Iterator) const [with _Value = const double; _Iterator = std::__detail::_Node_iterator<std::pair<const int, int>, false, false>]':
/usr/include/c++/10/bits/stl_algo.h:2061:14:   required from '_ForwardIterator std::__upper_bound(_ForwardIterator, _ForwardIterator, const _Tp&, _Compare) [with _ForwardIterator = std::__detail::_Node_iterator<std::pair<const int, int>, false, false>; _Tp = double; _Compare = __gnu_cxx::__ops::_Val_less_iter]'
/usr/include/c++/10/bits/stl_algo.h:2096:32:   required from '_FIter std::upper_bound(_FIter, _FIter, const _Tp&) [with _FIter = std::__detail::_Node_iterator<std::pair<const int, int>, false, false>; _Tp = double]'
regions.cpp:89:38:   required from here
/usr/include/c++/10/bits/predefined_ops.h:96:22: error: no match for 'operator<' (operand types are 'const double' and 'std::pair<const int, int>')
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:1096:5: note: candidate: 'template<class _IteratorL, class _IteratorR, class _Container> bool __gnu_cxx::operator<(const __gnu_cxx::__normal_iterator<_IteratorL, _Container>&, const __gnu_cxx::__normal_iterator<_IteratorR, _Container>&)'
 1096 |     operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:1096:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const __gnu_cxx::__normal_iterator<_IteratorL, _Container>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:1104:5: note: candidate: 'template<class _Iterator, class _Container> bool __gnu_cxx::operator<(const __gnu_cxx::__normal_iterator<_Iterator, _Container>&, const __gnu_cxx::__normal_iterator<_Iterator, _Container>&)'
 1104 |     operator<(const __normal_iterator<_Iterator, _Container>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:1104:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const __gnu_cxx::__normal_iterator<_Iterator, _Container>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from regions.cpp:1:
/usr/include/c++/10/bits/regex.h:1075:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const std::__cxx11::sub_match<_BiIter>&)'
 1075 |     operator<(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1075:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from regions.cpp:1:
/usr/include/c++/10/bits/regex.h:1156:5: 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>&)'
 1156 |     operator<(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1156:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from regions.cpp:1:
/usr/include/c++/10/bits/regex.h:1249:5: 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>&)'
 1249 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1249:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from regions.cpp:1:
/usr/include/c++/10/bits/regex.h:1323:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type*, const std::__cxx11::sub_match<_BiIter>&)'
 1323 |     operator<(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1323:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   'std::pair<const int, int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from regions.cpp:1:
/usr/include/c++/10/bits/regex.h:1417:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1417 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1417:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from regions.cpp:1:
/usr/include/c++/10/bits/regex.h:1492:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type&, const std::__cxx11::sub_match<_BiIter>&)'
 1492 |     operator<(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1492:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   'std::pair<const int, int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from regions.cpp:1:
/usr/include/c++/10/bits/regex.h:1592:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1592 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1592:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/stl_algobase.h:64,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/stl_pair.h:489:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)'
  489 |     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_pair.h:489:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::pair<_T1, _T2>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:366:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)'
  366 |     operator<(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:366:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:404:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)'
  404 |     operator<(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:404:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:1451:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)'
 1451 |     operator<(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:1451:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:1507:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)'
 1507 |     operator<(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:1507:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from regions.cpp:1:
/usr/include/c++/10/bits/predefined_ops.h:96:22: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'const double'
   96 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/10/bits/basic_string.h:48,
                 from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from regions.cpp:1:
/usr/include/c++/10/string_view:544:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(std::basic_string_view<_CharT, _Traits>, std::basic_string_view<_CharT, _Traits>)'
  544 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/10/string_view:544:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/10/bits/stl_algobase.h:71,