horses.cpp:102:19: error: use of deleted function 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set() [with _Value = std::pair<int, int>; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
102 | unordered_set<pii>seg;
| ^~~
In file included from /usr/include/c++/13/unordered_set:41,
from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:189,
from horses.cpp:6:
/usr/include/c++/13/bits/unordered_set.h:142:7: note: 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set() [with _Value = std::pair<int, int>; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]' is implicitly deleted because the default definition would be ill-formed:
142 | unordered_set() = default;
| ^~~~~~~~~~~~~
/usr/include/c++/13/bits/unordered_set.h:142:7: error: use of deleted function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_Hashtable() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>]'
In file included from /usr/include/c++/13/bits/unordered_map.h:33,
from /usr/include/c++/13/unordered_map:41,
from /usr/include/c++/13/functional:63,
from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:53:
/usr/include/c++/13/bits/hashtable.h:530:7: note: 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_Hashtable() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>]' is implicitly deleted because the default definition would be ill-formed:
530 | _Hashtable() = default;
| ^~~~~~~~~~
/usr/include/c++/13/bits/hashtable.h:530:7: error: use of deleted function 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _Traits>::_Hashtable_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, true, true>]'
In file included from /usr/include/c++/13/bits/hashtable.h:35:
/usr/include/c++/13/bits/hashtable_policy.h:1701:7: note: 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _Traits>::_Hashtable_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, true, true>]' is implicitly deleted because the default definition would be ill-formed:
1701 | _Hashtable_base() = default;
| ^~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1701:7: error: use of deleted function 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::_Hash_code_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true]'
/usr/include/c++/13/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hashtable_ebo_helper<_Nm, _Tp, true>::_Hashtable_ebo_helper() [with int _Nm = 1; _Tp = std::hash<std::pair<int, int> >]':
/usr/include/c++/13/bits/hashtable_policy.h:1301:7: required from here
/usr/include/c++/13/bits/hashtable_policy.h:1218:49: error: use of deleted function 'std::hash<std::pair<int, int> >::hash()'
1218 | _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { }
| ^~~~~
In file included from /usr/include/c++/13/string_view:42,
from /usr/include/c++/13/bits/basic_string.h:47,
from /usr/include/c++/13/string:54,
from /usr/include/c++/13/bitset:52,
from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:52:
/usr/include/c++/13/bits/functional_hash.h:102:12: note: 'std::hash<std::pair<int, int> >::hash()' is implicitly deleted because the default definition would be ill-formed:
102 | struct hash : __hash_enum<_Tp>
| ^~~~
/usr/include/c++/13/bits/functional_hash.h:102:12: error: no matching function for call to 'std::__hash_enum<std::pair<int, int>, false>::__hash_enum()'
/usr/include/c++/13/bits/functional_hash.h:83:7: note: candidate: 'std::__hash_enum<_Tp, <anonymous> >::__hash_enum(std::__hash_enum<_Tp, <anonymous> >&&) [with _Tp = std::pair<int, int>; bool <anonymous> = false]'
83 | __hash_enum(__hash_enum&&);
| ^~~~~~~~~~~
/usr/include/c++/13/bits/functional_hash.h:83:7: note: candidate expects 1 argument, 0 provided
/usr/include/c++/13/bits/functional_hash.h:102:12: error: 'std::__hash_enum<_Tp, <anonymous> >::~__hash_enum() [with _Tp = std::pair<int, int>; bool <anonymous> = false]' is private within this context
102 | struct hash : __hash_enum<_Tp>
| ^~~~
/usr/include/c++/13/bits/functional_hash.h:84:7: note: declared private here
84 | ~__hash_enum();
| ^
/usr/include/c++/13/bits/hashtable_policy.h:1301:7: note: 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::_Hash_code_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true]' is implicitly deleted because the default definition would be ill-formed:
1301 | _Hash_code_base() = default;
| ^~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1301:7: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()'
/usr/include/c++/13/bits/hashtable_policy.h:1215:12: note: 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()' is implicitly deleted because the default definition would be ill-formed:
1215 | struct _Hashtable_ebo_helper<_Nm, _Tp, true>
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1215:12: error: use of deleted function 'std::hash<std::pair<int, int> >::~hash()'
/usr/include/c++/13/bits/functional_hash.h:102:12: note: 'std::hash<std::pair<int, int> >::~hash()' is implicitly deleted because the default definition would be ill-formed:
102 | struct hash : __hash_enum<_Tp>
| ^~~~
/usr/include/c++/13/bits/functional_hash.h:102:12: error: 'std::__hash_enum<_Tp, <anonymous> >::~__hash_enum() [with _Tp = std::pair<int, int>; bool <anonymous> = false]' is private within this context
/usr/include/c++/13/bits/functional_hash.h:84:7: note: declared private here
84 | ~__hash_enum();
| ^
/usr/include/c++/13/bits/hashtable_policy.h:1701:7: error: use of deleted function 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()'
1701 | _Hashtable_base() = default;
| ^~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1279:12: note: 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()' is implicitly deleted because the default definition would be ill-formed:
1279 | struct _Hash_code_base
| ^~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1279:12: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()'
/usr/include/c++/13/bits/hashtable.h:530:7: error: use of deleted function 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Hashtable_traits<true, true, true> >::~_Hashtable_base()'
530 | _Hashtable() = default;
| ^~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1658:12: note: 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Hashtable_traits<true, true, true> >::~_Hashtable_base()' is implicitly deleted because the default definition would be ill-formed:
1658 | struct _Hashtable_base
| ^~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1658:12: error: use of deleted function 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()'
/usr/include/c++/13/bits/hashtable.h:530:7: error: use of deleted function 'constexpr std::_Enable_default_constructor<false, _Tag>::_Enable_default_constructor() [with _Tag = std::__detail::_Hash_node_base]'
530 | _Hashtable() = default;
| ^~~~~~~~~~
In file included from /usr/include/c++/13/bits/hashtable.h:36:
/usr/include/c++/13/bits/enable_special_members.h:113:15: note: declared here
113 | constexpr _Enable_default_constructor() noexcept = delete;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
horses.cpp: In function 'int ans()':
horses.cpp:112:29: error: 'class std::unordered_set<std::pair<int, int> >' has no member named 'rbegin'; did you mean 'begin'?
112 | pii b=*(seg.rbegin());
| ^~~~~~
| begin
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:201:28: error: 'class std::unordered_set<std::pair<int, int> >' has no member named 'lower_bound'
201 | auto p=seg.lower_bound(pai(i,0));
| ^~~~~~~~~~~
horses.cpp:206:27: error: 'b' was not declared in this scope
206 | seg.erase(b);
| ^
horses.cpp:210:28: error: 'class std::unordered_set<std::pair<int, int> >' has no member named 'lower_bound'
210 | auto p=seg.lower_bound(pai(i,0));
| ^~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::__hash_code std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::_M_hash_code(const _Key&) const [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true; __hash_code = long unsigned int]':
/usr/include/c++/13/bits/hashtable.h:2384:43: required from 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::size_type std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_M_erase(std::true_type, const key_type&) [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>; size_type = long unsigned int; std::true_type = std::integral_constant<bool, true>; key_type = std::pair<int, int>]'
/usr/include/c++/13/bits/hashtable.h:984:24: required from 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::size_type std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::erase(const key_type&) [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>; size_type = long unsigned int; key_type = std::pair<int, int>]'
/usr/include/c++/13/bits/unordered_set.h:553:26: required from 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::size_type std::unordered_set<_Value, _Hash, _Pred, _Alloc>::erase(const key_type&) [with _Value = std::pair<int, int>; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; size_type = long unsigned int; key_type = std::pair<int, int>]'
horses.cpp:114:12: required from here
/usr/include/c++/13/bits/hashtable_policy.h:1308:23: error: static assertion failed: hash function must be invocable with an argument of key type
1308 | static_assert(__is_invocable<const _Hash&, const _Key&>{},
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1308:23: note: 'std::__is_invocable<const std::hash<std::pair<int, int> >&, const std::pair<int, int>&>()' evaluates to false
/usr/include/c++/13/bits/hashtable_policy.h:1310:25: error: no match for call to '(const std::hash<std::pair<int, int> >) (const std::pair<int, int>&)'
1310 | return _M_hash()(__k);
| ~~~~~~~~~^~~~~
/usr/include/c++/13/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::__hash_code std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::_M_hash_code_tr(const _Kt&) const [with _Kt = std::pair<int, int>; _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true; __hash_code = long unsigned int]':
/usr/include/c++/13/bits/hashtable.h:2264:44: required from 'std::pair<typename std::__detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator, bool> std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_M_insert_unique(_Kt&&, _Arg&&, const _NodeGenerator&) [with _Kt = const std::pair<int, int>&; _Arg = const std::pair<int, int>&; _NodeGenerator = std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<std::pair<int, int>, true> > >; _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>; typename std::__detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<int, int>, std::allocator<std::pair<int, int> >, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, true, true> >::iterator; typename _Traits::__constant_iterators = std::__detail::_Hashtable_traits<true, true, true>::__constant_iterators]'
/usr/include/c++/13/bits/hashtable.h:904:27: required from 'std::pair<typename std::__detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator, bool> std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_M_insert_unique_aux(_Arg&&, const _NodeGenerator&) [with _Arg = const std::pair<int, int>&; _NodeGenerator = std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<std::pair<int, int>, true> > >; _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>; typename std::__detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<int, int>, std::allocator<std::pair<int, int> >, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, true, true> >::iterator; typename _Traits::__constant_iterators = std::__detail::_Hashtable_traits<true, true, true>::__constant_iterators]'
/usr/include/c++/13/bits/hashtable.h:916:31: required from 'std::pair<typename std::__detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator, bool> std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_M_insert(_Arg&&, const _NodeGenerator&, std::true_type) [with _Arg = const std::pair<int, int>&; _NodeGenerator = std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<std::pair<int, int>, true> > >; _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>; typename std::__detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<int, int>, std::allocator<std::pair<int, int> >, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, true, true> >::iterator; typename _Traits::__constant_iterators = std::__detail::_Hashtable_traits<true, true, true>::__constant_iterators; std::true_type = std::integral_constant<bool, true>]'
/usr/include/c++/13/bits/hashtable_policy.h:933:22: required from 'std::__detail::_Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::__ireturn_type std::__detail::_Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::insert(const value_type&) [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>; __ireturn_type = std::__detail::_Insert_base<std::pair<int, int>, std::pair<int, int>, std::allocator<std::pair<int, int> >, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, true, true> >::__ireturn_type; value_type = std::pair<int, int>]'
/usr/include/c++/13/bits/unordered_set.h:429:27: required from 'std::pair<typename std::_Hashtable<_Value, _Value, _Alloc, std::__detail::_Identity, _Pred, _Hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>, std::__is_nothrow_invocable<const _Hash&, const _Tp&> > >::value, true, true> >::iterator, bool> std::unordered_set<_Value, _Hash, _Pred, _Alloc>::insert(const value_type&) [with _Value = std::pair<int, int>; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; typename std::_Hashtable<_Value, _Value, _Alloc, std::__detail::_Identity, _Pred, _Hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>, std::__is_nothrow_invocable<const _Hash&, const _Tp&> > >::value, true, true> >::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<int, int>, std::allocator<std::pair<int, int> >, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, true, true> >::iterator; value_type = std::pair<int, int>]'
horses.cpp:135:13: required from here
/usr/include/c++/13/bits/hashtable_policy.h:1317:25: error: static assertion failed: hash function must be invocable with an argument of key type
1317 | static_assert(__is_invocable<const _Hash&, const _Kt&>{},
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/13/bits/hashtable_policy.h:1317:25: note: 'std::__is_invocable<const std::hash<std::pair<int, int> >&, const std::pair<int, int>&>()' evaluates to false
/usr/include/c++/13/bits/hashtable_policy.h:1319:27: error: no match for call to '(const std::hash<std::pair<int, int> >) (const std::pair<int, int>&)'
1319 | return _M_hash()(__k);
| ~~~~~~~~~^~~~~
/usr/include/c++/13/bits/hashtable.h: In instantiation of 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::~_Hashtable() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>]':
/usr/include/c++/13/bits/unordered_set.h:104:11: required from here
/usr/include/c++/13/bits/hashtable.h:1610:5: error: use of deleted function 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Hashtable_traits<true, true, true> >::~_Hashtable_base()'
1610 | }
| ^