Submission #1011386

# Submission time Handle Problem Language Result Execution time Memory
1011386 2024-06-30T12:52:43 Z Double_Slash Languages (IOI10_languages) C++17
Compilation error
0 ms 0 KB
#include "lang.h"
#include "grader.h"
#include <bits/stdc++.h>
 
using namespace std;
#define debug(x) [&] { auto _x = x; cerr << __LINE__ << ": " << #x << " = " << _x << endl; return _x; }()
using pint = pair<int, int>;

const int MAX = 100;
 
double magic(double x) {
	return pow(abs(x), 1.2);
}
 
template <typename T>
struct Data : map<T, int> {
	int tot = 0;
  set<pair<int, T>> inv;
 
	double operator&(const Data<T> &o) const {
		double ret = 0;
		for (auto [k, v]: *this) {
			ret += magic((double) v / tot - (o.count(k) ? (double) o.at(k) / o.tot : 0));
		}
		for (auto [k, v]: o) {
			if (not this->count(k)) ret += magic((double) v / o.tot);
		}
		return ret;
	}
 
	void operator+=(const Data<T> &o) {
		for (auto &[k, v]: o) {
          inv.erase(pair<int, T>{v, (*this)[k]});
			inv.emplace(v, (*this)[k] += v);
		}
		tot += o.tot;
      while (inv.size() > MAX) {
          tot -= inv.begin()->first;
          this->erase(inv.begin()->second);
}
	}};
 
struct Profile {
  Data<pint> doub;
 
	Profile() {}
 
	Profile(int *arr) {
		for (int i = 0; i < 100; ++i) {
          if (i) doub[{arr[i - 1], arr[i]}]++;
		}
      for (auto [k, v]: doub) doub.inv.emplace(v, k);
      doub.tot = 99;
	}
 
	double operator&(const Profile &o) const {
		return (doub & o.doub);
	}
 
	void operator+=(const Profile &o) {
      doub += o.doub;
	}
} profile[56];
 
void excerpt(int *E) {
	Profile p(E);
	pair<double, int> mn{1e18, 0};
	for (int i = 0; i < 56; ++i) {
		mn = min(mn, {p & profile[i], i});
	}
	int ans = language(mn.second);
	profile[ans] += p;
}

Compilation message

lang.cpp: In instantiation of 'void Data<T>::operator+=(const Data<T>&) [with T = std::pair<int, int>]':
lang.cpp:61:17:   required from here
lang.cpp:33:20: error: no matching function for call to 'std::pair<int, std::pair<int, int> >::pair(<brace-enclosed initializer list>)'
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:452:9: note: candidate: 'template<class ... _Args1, long unsigned int ..._Indexes1, class ... _Args2, long unsigned int ..._Indexes2> std::pair<_T1, _T2>::pair(std::tuple<_Args1 ...>&, std::tuple<_Args2 ...>&, std::_Index_tuple<_Indexes1 ...>, std::_Index_tuple<_Indexes2 ...>) [with _Args1 = {_Args1 ...}; long unsigned int ..._Indexes1 = {_Indexes1 ...}; _Args2 = {_Args2 ...}; long unsigned int ..._Indexes2 = {_Indexes2 ...}; _T1 = int; _T2 = std::pair<int, int>]'
  452 |         pair(tuple<_Args1...>&, tuple<_Args2...>&,
      |         ^~~~
/usr/include/c++/10/bits/stl_pair.h:452:9: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   mismatched types 'std::tuple<_Tps ...>' and 'std::tuple_element<1, const std::pair<const std::pair<int, int>, int> >::type' {aka 'const int'}
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:387:9: note: candidate: 'template<class ... _Args1, class ... _Args2> std::pair<_T1, _T2>::pair(std::piecewise_construct_t, std::tuple<_Args1 ...>, std::tuple<_Args2 ...>) [with _Args1 = {_Args1 ...}; _Args2 = {_Args2 ...}; _T1 = int; _T2 = std::pair<int, int>]'
  387 |         pair(piecewise_construct_t, tuple<_Args1...>, tuple<_Args2...>);
      |         ^~~~
/usr/include/c++/10/bits/stl_pair.h:387:9: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   mismatched types 'std::tuple<_Tps ...>' and 'int'
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:381:21: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_MoveConstructiblePair<_U1, _U2>() && (! std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(std::pair<_U1, _U2>&&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && (! std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  381 |  explicit constexpr pair(pair<_U1, _U2>&& __p)
      |                     ^~~~
/usr/include/c++/10/bits/stl_pair.h:381:21: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   mismatched types 'std::pair<_T1, _T2>' and 'std::tuple_element<1, const std::pair<const std::pair<int, int>, int> >::type' {aka 'const int'}
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:371:12: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_MoveConstructiblePair<_U1, _U2>() && std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(std::pair<_U1, _U2>&&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  371 |  constexpr pair(pair<_U1, _U2>&& __p)
      |            ^~~~
/usr/include/c++/10/bits/stl_pair.h:371:12: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   mismatched types 'std::pair<_T1, _T2>' and 'std::tuple_element<1, const std::pair<const std::pair<int, int>, int> >::type' {aka 'const int'}
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:361:21: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(_MoveConstructiblePair<_U1, _U2>() && (! _ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<true, _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && (! std::_PCC<true, _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>())), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  361 |  explicit constexpr pair(_U1&& __x, _U2&& __y)
      |                     ^~~~
/usr/include/c++/10/bits/stl_pair.h:361:21: note:   template argument deduction/substitution failed:
/usr/include/c++/10/bits/stl_pair.h:360:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  360 |                          bool>::type=false>
      |                                      ^~~~~
/usr/include/c++/10/bits/stl_pair.h:352:12: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(_MoveConstructiblePair<_U1, _U2>() && _ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<true, _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && std::_PCC<true, _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  352 |  constexpr pair(_U1&& __x, _U2&& __y)
      |            ^~~~
/usr/include/c++/10/bits/stl_pair.h:352:12: note:   template argument deduction/substitution failed:
/usr/include/c++/10/bits/stl_pair.h:351:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  351 |                          bool>::type=true>
      |                                      ^~~~
/usr/include/c++/10/bits/stl_pair.h:343:17: note: candidate: 'template<class _U2, typename std::enable_if<_CopyMovePair<false, int, _U2>(), bool>::type <anonymous> > std::pair<_T1, _T2>::pair(const _T1&, _U2&&) [with _U2 = _U2; typename std::enable_if<std::_PCC<true, _T1, _T2>::_CopyMovePair<false, _T1, _U2>(), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  343 |        explicit pair(const _T1& __x, _U2&& __y)
      |                 ^~~~
/usr/include/c++/10/bits/stl_pair.h:343:17: note:   template argument deduction/substitution failed:
/usr/include/c++/10/bits/stl_pair.h:342:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  342 |                          bool>::type=false>
      |                                      ^~~~~
/usr/include/c++/10/bits/stl_pair.h:336:18: note: candidate: 'template<class _U2, typename std::enable_if<_CopyMovePair<true, int, _U2>(), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(const _T1&, _U2&&) [with _U2 = _U2; typename std::enable_if<std::_PCC<true, _T1, _T2>::_CopyMovePair<true, _T1, _U2>(), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  336 |        constexpr pair(const _T1& __x, _U2&& __y)
      |                  ^~~~
/usr/include/c++/10/bits/stl_pair.h:336:18: note:   template argument deduction/substitution failed:
/usr/include/c++/10/bits/stl_pair.h:335:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  335 |                          bool>::type=true>
      |                                      ^~~~
/usr/include/c++/10/bits/stl_pair.h:329:27: note: candidate: 'template<class _U1, typename std::enable_if<_MoveCopyPair<false, _U1, std::pair<int, int> >(), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, const _T2&) [with _U1 = _U1; typename std::enable_if<std::_PCC<true, _T1, _T2>::_MoveCopyPair<false, _U1, _T2>(), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  329 |        explicit constexpr pair(_U1&& __x, const _T2& __y)
      |                           ^~~~
/usr/include/c++/10/bits/stl_pair.h:329:27: note:   template argument deduction/substitution failed:
/usr/include/c++/10/bits/stl_pair.h:328:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  328 |                          bool>::type=false>
      |                                      ^~~~~
/usr/include/c++/10/bits/stl_pair.h:322:18: note: candidate: 'template<class _U1, typename std::enable_if<_MoveCopyPair<true, _U1, std::pair<int, int> >(), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(_U1&&, const _T2&) [with _U1 = _U1; typename std::enable_if<std::_PCC<true, _T1, _T2>::_MoveCopyPair<true, _U1, _T2>(), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  322 |        constexpr pair(_U1&& __x, const _T2& __y)
      |                  ^~~~
/usr/include/c++/10/bits/stl_pair.h:322:18: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   cannot convert '((Data<std::pair<int, int> >*)this)->Data<std::pair<int, int> >::<anonymous>.std::map<std::pair<int, int>, int, std::less<std::pair<int, int> >, std::allocator<std::pair<const std::pair<int, int>, int> > >::operator[]((* & k))' (type 'std::map<std::pair<int, int>, int, std::less<std::pair<int, int> >, std::allocator<std::pair<const std::pair<int, int>, int> > >::mapped_type' {aka 'int'}) to type 'const std::pair<int, int>&'
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:315:17: note: candidate: 'constexpr std::pair<_T1, _T2>::pair(std::pair<_T1, _T2>&&) [with _T1 = int; _T2 = std::pair<int, int>]'
  315 |       constexpr pair(pair&&) = default;  ///< Move constructor
      |                 ^~~~
/usr/include/c++/10/bits/stl_pair.h:315:17: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/10/bits/stl_pair.h:314:17: note: candidate: 'constexpr std::pair<_T1, _T2>::pair(const std::pair<_T1, _T2>&) [with _T1 = int; _T2 = std::pair<int, int>]'
  314 |       constexpr pair(const pair&) = default; ///< Copy constructor
      |                 ^~~~
/usr/include/c++/10/bits/stl_pair.h:314:17: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/10/bits/stl_pair.h:309:21: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_ConstructiblePair<_U1, _U2>() && (! std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_ImplicitlyConvertiblePair<_U1, _U2>())), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(const std::pair<_U1, _U2>&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ConstructiblePair<_U1, _U2>() && (! std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ImplicitlyConvertiblePair<_U1, _U2>())), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  309 |  explicit constexpr pair(const pair<_U1, _U2>& __p)
      |                     ^~~~
/usr/include/c++/10/bits/stl_pair.h:309:21: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   mismatched types 'const std::pair<_T1, _T2>' and 'std::tuple_element<1, const std::pair<const std::pair<int, int>, int> >::type' {aka 'const int'}
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:300:19: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_ConstructiblePair<_U1, _U2>() && std::_PCC<((! std::is_same<int, _U1>::value) || (! std::is_same<std::pair<int, int>, _U2>::value)), int, std::pair<int, int> >::_ImplicitlyConvertiblePair<_U1, _U2>()), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(const std::pair<_U1, _U2>&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ConstructiblePair<_U1, _U2>() && std::_PCC<((! std::is_same<_T1, _U1>::value) || (! std::is_same<_T2, _U2>::value)), _T1, _T2>::_ImplicitlyConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  300 |         constexpr pair(const pair<_U1, _U2>& __p)
      |                   ^~~~
/usr/include/c++/10/bits/stl_pair.h:300:19: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   mismatched types 'const std::pair<_T1, _T2>' and 'std::tuple_element<1, const std::pair<const std::pair<int, int>, int> >::type' {aka 'const int'}
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:276:26: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(_ConstructiblePair<_U1, _U2>() && (! _ImplicitlyConvertiblePair<_U1, _U2>())), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(const _T1&, const _T2&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<true, _T1, _T2>::_ConstructiblePair<_U1, _U2>() && (! std::_PCC<true, _T1, _T2>::_ImplicitlyConvertiblePair<_U1, _U2>())), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  276 |       explicit constexpr pair(const _T1& __a, const _T2& __b)
      |                          ^~~~
/usr/include/c++/10/bits/stl_pair.h:276:26: note:   template argument deduction/substitution failed:
/usr/include/c++/10/bits/stl_pair.h:275:38: error: no type named 'type' in 'struct std::enable_if<false, bool>'
  275 |                          bool>::type=false>
      |                                      ^~~~~
/usr/include/c++/10/bits/stl_pair.h:266:17: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<(_ConstructiblePair<_U1, _U2>() && _ImplicitlyConvertiblePair<_U1, _U2>()), bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair(const _T1&, const _T2&) [with _U1 = _U1; _U2 = _U2; typename std::enable_if<(std::_PCC<true, _T1, _T2>::_ConstructiblePair<_U1, _U2>() && std::_PCC<true, _T1, _T2>::_ImplicitlyConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = <anonymous>; _T1 = int; _T2 = std::pair<int, int>]'
  266 |       constexpr pair(const _T1& __a, const _T2& __b)
      |                 ^~~~
/usr/include/c++/10/bits/stl_pair.h:266:17: note:   template argument deduction/substitution failed:
lang.cpp:33:20: note:   cannot convert '((Data<std::pair<int, int> >*)this)->Data<std::pair<int, int> >::<anonymous>.std::map<std::pair<int, int>, int, std::less<std::pair<int, int> >, std::allocator<std::pair<const std::pair<int, int>, int> > >::operator[]((* & k))' (type 'std::map<std::pair<int, int>, int, std::less<std::pair<int, int> >, std::allocator<std::pair<const std::pair<int, int>, int> > >::mapped_type' {aka 'int'}) to type 'const std::pair<int, int>&'
   33 |           inv.erase(pair<int, T>{v, (*this)[k]});
      |           ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 lang.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:245:26: note: candidate: 'template<class _U1, class _U2, typename std::enable_if<std::__and_<std::is_default_constructible<_U1>, std::is_default_constructible<_U2>, std::__not_<std::__and_<std::__is_implicitly_default_constructible<_U1>, std::__is_implicitly_default_constructible<_U2> > > >::value, bool>::type <anonymous> > constexpr std::pair<_T1, _T2>::pair() [with _U1 = _U1; _U2 = _U2; typename std::enable_if<std::__and_<std::is_default_constructible<_U1>, std::is_defaul