In file included from /usr/include/c++/7/bits/hashtable.h:35:0, from /usr/include/c++/7/unordered_map:47, from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:117, from Main.cc:1: /usr/include/c++/7/bits/hashtable_policy.h: In instantiation of ‘struct std::__detail::__is_noexcept_hash, std::hash > >’: /usr/include/c++/7/type_traits:143:12: required from ‘struct std::__and_ > >, std::__detail::__is_noexcept_hash, std::hash > > >’ /usr/include/c++/7/type_traits:154:31: required from ‘struct std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ /usr/include/c++/7/bits/unordered_map.h:103:66: required from ‘class std::unordered_map, bool>’ Main.cc:25:27: required from here /usr/include/c++/7/bits/hashtable_policy.h:87:34: error: no match for call to ‘(const std::hash >) (const std::pair&)’ noexcept(declval()(declval()))> ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ In file included from /usr/include/c++/7/bits/move.h:54:0, from /usr/include/c++/7/bits/nested_exception.h:40, from /usr/include/c++/7/exception:143, from /usr/include/c++/7/ios:39, from /usr/include/c++/7/istream:38, from /usr/include/c++/7/sstream:38, from /usr/include/c++/7/complex:45, from /usr/include/c++/7/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52, from Main.cc:1: /usr/include/c++/7/type_traits: In instantiation of ‘struct std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’: /usr/include/c++/7/bits/unordered_map.h:103:66: required from ‘class std::unordered_map, bool>’ Main.cc:25:27: required from here /usr/include/c++/7/type_traits:154:31: error: ‘value’ is not a member of ‘std::__and_ > >, std::__detail::__is_noexcept_hash, std::hash > > >’ : public __bool_constant ^~~~~~~~~~~~~~~~ In file included from /usr/include/c++/7/unordered_map:48:0, from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:117, from Main.cc:1: /usr/include/c++/7/bits/unordered_map.h: In instantiation of ‘class std::unordered_map, bool>’: Main.cc:25:27: required from here /usr/include/c++/7/bits/unordered_map.h:103:66: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef __umap_hashtable<_Key, _Tp, _Hash, _Pred, _Alloc> _Hashtable; ^~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:110:45: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::key_type key_type; ^~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:111:47: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::value_type value_type; ^~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:112:48: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::mapped_type mapped_type; ^~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:113:43: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::hasher hasher; ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:114:46: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::key_equal key_equal; ^~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:115:51: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::allocator_type allocator_type; ^~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:120:45: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::pointer pointer; ^~~~~~~ /usr/include/c++/7/bits/unordered_map.h:121:50: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::const_pointer const_pointer; ^~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:122:47: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::reference reference; ^~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:123:52: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::const_reference const_reference; ^~~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:124:46: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::iterator iterator; ^~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:125:51: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::const_iterator const_iterator; ^~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:126:51: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::local_iterator local_iterator; ^~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:127:57: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::const_local_iterator const_local_iterator; ^~~~~~~~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:128:47: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::size_type size_type; ^~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:129:52: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ typedef typename _Hashtable::difference_type difference_type; ^~~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:288:7: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ operator=(initializer_list __l) ^~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:386:2: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ emplace(_Args&&... __args) ^~~~~~~ /usr/include/c++/7/bits/unordered_map.h:578:7: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ insert(const value_type& __x) ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:584:7: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ insert(value_type&& __x) ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:590:2: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ insert(_Pair&& __x) ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:628:2: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ insert(const_iterator __hint, _Pair&& __x) ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:654:7: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ insert(initializer_list __l) ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:950:7: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ equal_range(const key_type& __x) ^~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:954:7: error: ‘value’ is not a member of ‘std::__not_ > >, std::__detail::__is_noexcept_hash, std::hash > > > >’ equal_range(const key_type& __x) const ^~~~~~~~~~~ Main.cc: In function ‘void dfs(long long int, long long int)’: Main.cc:31:15: error: no match for ‘operator[]’ (operand types are ‘std::unordered_map, bool>’ and ‘std::pair’) mp[mkp(st[top].fir, st[top].sec)] = 1, ^ Main.cc:32:15: error: no match for ‘operator[]’ (operand types are ‘std::unordered_map, bool>’ and ‘std::pair’) mp[mkp(st[top].sec, st[top].fir)] = 1, ^ Main.cc:34:11: error: no match for ‘operator[]’ (operand types are ‘std::unordered_map, bool>’ and ‘std::pair’) mp[mkp(st[top].fir, st[top].sec)] = 1, ^ Main.cc:35:11: error: no match for ‘operator[]’ (operand types are ‘std::unordered_map, bool>’ and ‘std::pair’) mp[mkp(st[top].sec, st[top].fir)] = 1, ^ In file included from /usr/include/c++/7/bits/hashtable.h:35:0, from /usr/include/c++/7/unordered_map:47, from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:117, from Main.cc:1: /usr/include/c++/7/bits/hashtable_policy.h: In instantiation of ‘struct std::__detail::__is_noexcept_hash >, std::hash > > >’: /usr/include/c++/7/type_traits:143:12: required from ‘struct std::__and_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > >’ /usr/include/c++/7/type_traits:154:31: required from ‘struct std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ /usr/include/c++/7/bits/unordered_map.h:103:66: required from ‘class std::unordered_map >, bool>’ Main.cc:54:39: required from here /usr/include/c++/7/bits/hashtable_policy.h:87:34: error: no match for call to ‘(const std::hash > >) (const std::pair >&)’ noexcept(declval()(declval()))> ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ In file included from /usr/include/c++/7/bits/move.h:54:0, from /usr/include/c++/7/bits/nested_exception.h:40, from /usr/include/c++/7/exception:143, from /usr/include/c++/7/ios:39, from /usr/include/c++/7/istream:38, from /usr/include/c++/7/sstream:38, from /usr/include/c++/7/complex:45, from /usr/include/c++/7/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:52, from Main.cc:1: /usr/include/c++/7/type_traits: In instantiation of ‘struct std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’: /usr/include/c++/7/bits/unordered_map.h:103:66: required from ‘class std::unordered_map >, bool>’ Main.cc:54:39: required from here /usr/include/c++/7/type_traits:154:31: error: ‘value’ is not a member of ‘std::__and_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > >’ : public __bool_constant ^~~~~~~~~~~~~~~~ In file included from /usr/include/c++/7/unordered_map:48:0, from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:117, from Main.cc:1: /usr/include/c++/7/bits/unordered_map.h: In instantiation of ‘class std::unordered_map >, bool>’: Main.cc:54:39: required from here /usr/include/c++/7/bits/unordered_map.h:103:66: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef __umap_hashtable<_Key, _Tp, _Hash, _Pred, _Alloc> _Hashtable; ^~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:110:45: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::key_type key_type; ^~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:111:47: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::value_type value_type; ^~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:112:48: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::mapped_type mapped_type; ^~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:113:43: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::hasher hasher; ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:114:46: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::key_equal key_equal; ^~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:115:51: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::allocator_type allocator_type; ^~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:120:45: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::pointer pointer; ^~~~~~~ /usr/include/c++/7/bits/unordered_map.h:121:50: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::const_pointer const_pointer; ^~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:122:47: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::reference reference; ^~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:123:52: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::const_reference const_reference; ^~~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:124:46: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::iterator iterator; ^~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:125:51: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::const_iterator const_iterator; ^~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:126:51: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::local_iterator local_iterator; ^~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:127:57: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::const_local_iterator const_local_iterator; ^~~~~~~~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:128:47: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::size_type size_type; ^~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:129:52: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ typedef typename _Hashtable::difference_type difference_type; ^~~~~~~~~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:288:7: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ operator=(initializer_list __l) ^~~~~~~~ /usr/include/c++/7/bits/unordered_map.h:386:2: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ emplace(_Args&&... __args) ^~~~~~~ /usr/include/c++/7/bits/unordered_map.h:578:7: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ insert(const value_type& __x) ^~~~~~ /usr/include/c++/7/bits/unordered_map.h:584:7: error: ‘value’ is not a member of ‘std::__not_ > > >, std::__detail::__is_noexcept_hash >, std::hash > > > > >’ insert(value_type&& __x)