# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1229214 | Ludissey | Keys (IOI21_keys) | C++20 | Compilation error | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
#define all(a) (a.begin(), a.end())
#define rall(a) a.rbegin(), a.rend()
#define sz(a) (int)a.size()
vector<int> sz,parent;
vector<vector<int>> neigh;
vector<vector<int>> neighu;
vector<int> topo;
vector<int> visited;
bool unt=true;
int geP(int a){
if(parent[a]==a) return a;
return parent[a]=geP(parent[a]);
}
void unite(int a, int b){
a=geP(a);
b=geP(b);
if(a==b) return;
if(sz[a]<sz[b]){
swap(a,b);
}
sz[a]+=sz[b];
parent[b]=a;
}
bool same(int a, int b){
a=geP(a);
b=geP(b);
return (a==b);
}
void dfs1(int x){
if(visited[x]==1) return;
visited[x]=1;
for (auto u : neigh[x]) dfs1(u);
topo.push_back(x);
}
void dfs2(int x){
if(visited[x]==2) return;
visited[x]=2;
for (auto u : neighu[x]) {
if(visited[u]==2) continue;
unite(u,x);
unt=true;
dfs2(u);
}
}
std::vector<signed> find_reachable(std::vector<signed> _r, std::vector<signed> u, std::vector<signed> v, std::vector<signed> c) {
vector<int> r(sz(_r));
int n=sz(r);
for (int i = 0; i < n; i++)
{
r[i]=_r[i];
}
std::vector<signed> ans(n, 1);
neigh.resize(n);
neighu.resize(n);
for (int i = 0; i < sz(r); i++) r[i]=(1<<r[i]);
sz.resize(n,1);
parent.resize(n);
visited.resize(n);
topo.resize(n);
for (int i = 0; i < n; i++) parent[i]=i;
for (int i = 0; i < n; i++) sz[i]=1;
unt=true;
while(unt){
unt=false;
topo.clear();
for (int i = 0; i < n; i++) {
neigh[i].clear();
neighu[i].clear();
visited[i]=0;
}
for (int i = 0; i < n; i++) r[geP(i)]|=r[i];
unordered_map<pair<int,int>,int> ed;
for (int i = 0; i < sz(u); i++)
{
if(same(geP(u[i]),geP(v[i]))) continue;
if(ed.find({min(geP(u[i]),geP(v[i])),max(geP(u[i]),geP(v[i]))})==ed.end()) ed[{min(geP(u[i]),geP(v[i])),max(geP(u[i]),geP(v[i]))}]=0;
ed[{min(geP(u[i]),geP(v[i])),max(geP(u[i]),geP(v[i]))}]|=(1<<(int)c[i]);
}
for (auto u : ed)
{
if(r[geP(u.first.first)]&u.second){
neigh[geP(u.first.first)].push_back(geP(u.first.second));
neighu[geP(u.first.second)].push_back(geP(u.first.first));
}if(r[geP(u.first.second)]&u.second){
neigh[geP(u.first.second)].push_back(geP(u.first.first));
neighu[geP(u.first.first)].push_back(geP(u.first.second));
}
}
for (int i = 0; i < n; i++) dfs1(geP(i));
for (int i = 0; i < n; i++){
dfs2(geP(topo[(n-1)-i]));
}
}
int mn=1e9;
for (int i = 0; i < n; i++){
if(sz(neigh[geP(i)])==0) mn=min(sz[geP(i)],mn);
}
for (int i = 0; i < n; i++){
ans[i]=(mn==sz[geP(i)]&&sz(neigh[geP(i)])==0);
}
return ans;
}
Compilation message (stderr)
keys.cpp: In function 'std::vector<int> find_reachable(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)': keys.cpp:85:50: error: use of deleted function 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map() [with _Key = std::pair<int, int>; _Tp = int; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >]' 85 | unordered_map<pair<int,int>,int> ed; | ^~ In file included from /usr/include/c++/11/unordered_map:47, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/unordered_map.h:141:7: note: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map() [with _Key = std::pair<int, int>; _Tp = int; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >]' is implicitly deleted because the default definition would be ill-formed: 141 | unordered_map() = default; | ^~~~~~~~~~~~~ /usr/include/c++/11/bits/unordered_map.h:141:7: 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<const std::pair<int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; _ExtractKey = std::__detail::_Select1st; _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, false, true>]' In file included from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/hashtable.h:528:7: note: 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::_Hashtable() [with _Key = std::pair<int, int>; _Value = std::pair<const std::pair<int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; _ExtractKey = std::__detail::_Select1st; _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, false, true>]' is implicitly deleted because the default definition would be ill-formed: 528 | _Hashtable() = default; | ^~~~~~~~~~ /usr/include/c++/11/bits/hashtable.h:528:7: 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<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _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, false, true>]' In file included from /usr/include/c++/11/bits/hashtable.h:35, from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/hashtable_policy.h:1604:7: note: 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _Traits>::_Hashtable_base() [with _Key = std::pair<int, int>; _Value = std::pair<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _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, false, true>]' is implicitly deleted because the default definition would be ill-formed: 1604 | _Hashtable_base() = default; | ^~~~~~~~~~~~~~~ /usr/include/c++/11/bits/hashtable_policy.h:1604:7: 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<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _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++/11/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++/11/bits/hashtable_policy.h:1210:7: required from here /usr/include/c++/11/bits/hashtable_policy.h:1127:49: error: use of deleted function 'std::hash<std::pair<int, int> >::hash()' 1127 | _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { } | ^~~~~ In file included from /usr/include/c++/11/string_view:42, from /usr/include/c++/11/bits/basic_string.h:48, from /usr/include/c++/11/string:55, from /usr/include/c++/11/bits/locale_classes.h:40, from /usr/include/c++/11/bits/ios_base.h:41, from /usr/include/c++/11/ios:42, from /usr/include/c++/11/istream:38, from /usr/include/c++/11/sstream:38, from /usr/include/c++/11/complex:45, from /usr/include/c++/11/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54, from keys.cpp:1: /usr/include/c++/11/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++/11/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++/11/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++/11/bits/functional_hash.h:83:7: note: candidate expects 1 argument, 0 provided /usr/include/c++/11/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++/11/bits/functional_hash.h:84:7: note: declared private here 84 | ~__hash_enum(); | ^ In file included from /usr/include/c++/11/bits/hashtable.h:35, from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/hashtable_policy.h:1210:7: 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<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _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: 1210 | _Hash_code_base() = default; | ^~~~~~~~~~~~~~~ /usr/include/c++/11/bits/hashtable_policy.h:1210:7: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()' /usr/include/c++/11/bits/hashtable_policy.h:1124:12: 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: 1124 | struct _Hashtable_ebo_helper<_Nm, _Tp, true> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/bits/hashtable_policy.h:1124:12: error: use of deleted function 'std::hash<std::pair<int, int> >::~hash()' In file included from /usr/include/c++/11/string_view:42, from /usr/include/c++/11/bits/basic_string.h:48, from /usr/include/c++/11/string:55, from /usr/include/c++/11/bits/locale_classes.h:40, from /usr/include/c++/11/bits/ios_base.h:41, from /usr/include/c++/11/ios:42, from /usr/include/c++/11/istream:38, from /usr/include/c++/11/sstream:38, from /usr/include/c++/11/complex:45, from /usr/include/c++/11/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:54, from keys.cpp:1: /usr/include/c++/11/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++/11/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++/11/bits/functional_hash.h:84:7: note: declared private here 84 | ~__hash_enum(); | ^ In file included from /usr/include/c++/11/bits/hashtable.h:35, from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/hashtable_policy.h:1604:7: error: use of deleted function 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::__detail::_Select1st, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()' 1604 | _Hashtable_base() = default; | ^~~~~~~~~~~~~~~ /usr/include/c++/11/bits/hashtable_policy.h:1188:12: note: 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::__detail::_Select1st, 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: 1188 | struct _Hash_code_base | ^~~~~~~~~~~~~~~ /usr/include/c++/11/bits/hashtable_policy.h:1188:12: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()' In file included from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/hashtable.h:528:7: error: use of deleted function 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::__detail::_Select1st, 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, false, true> >::~_Hashtable_base()' 528 | _Hashtable() = default; | ^~~~~~~~~~ In file included from /usr/include/c++/11/bits/hashtable.h:35, from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/hashtable_policy.h:1561:12: note: 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::__detail::_Select1st, 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, false, true> >::~_Hashtable_base()' is implicitly deleted because the default definition would be ill-formed: 1561 | struct _Hashtable_base | ^~~~~~~~~~~~~~~ /usr/include/c++/11/bits/hashtable_policy.h:1561:12: error: use of deleted function 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::__detail::_Select1st, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()' In file included from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/hashtable.h:528:7: error: use of deleted function 'constexpr std::_Enable_default_constructor<false, _Tag>::_Enable_default_constructor() [with _Tag = std::__detail::_Hash_node_base]' 528 | _Hashtable() = default; | ^~~~~~~~~~ In file included from /usr/include/c++/11/bits/hashtable.h:36, from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/bits/enable_special_members.h:113:15: note: declared here 113 | constexpr _Enable_default_constructor() noexcept = delete; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/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<const std::pair<int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; _ExtractKey = std::__detail::_Select1st; _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, false, true>]': /usr/include/c++/11/bits/unordered_map.h:102:11: required from here /usr/include/c++/11/bits/hashtable.h:1534:5: error: use of deleted function 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::__detail::_Select1st, 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, false, true> >::~_Hashtable_base()' 1534 | } | ^ In file included from /usr/include/c++/11/bits/hashtable.h:35, from /usr/include/c++/11/unordered_map:46, from /usr/include/c++/11/functional:61, from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13, from /usr/include/c++/11/algorithm:74, from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65, from keys.cpp:1: /usr/include/c++/11/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<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _Hash = std::hash<std::pair<int, int> >; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true; std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::__hash_code = long unsigned int]': /usr/include/c++/11/bits/hashtable.h:1593:46: required from 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::find(const key_type&) [with _Key = std::pair<int, int>; _Value = std::pair<const std::pair<int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; _ExtractKey = std::__detail::_Select1st; _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, false, true>; std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::allocator<std::pair<const std::pair<int, int>, int> >, std::__detail::_Select1st, 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, false, true> >::iterator; std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::key_type = std::pair<int, int>]' /usr/include/c++/11/bits/unordered_map.h:869:25: required from 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::find(const key_type&) [with _Key = std::pair<int, int>; _Tp = int; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::allocator<std::pair<const std::pair<int, int>, int> >, std::__detail::_Select1st, 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, false, true> >::iterator; std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::key_type = std::pair<int, int>]' keys.cpp:89:14: required from here /usr/include/c++/11/bits/hashtable_policy.h:1217:23: error: static assertion failed: hash function must be invocable with an argument of key type 1217 | static_assert(__is_invocable<const _Hash&, const _Key&>{}, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/11/bits/hashtable_policy.h:1217:23: note: 'std::__is_invocable<const std::hash<std::pair<int, int> >&, const std::pair<int, int>&>{}' evaluates to false /usr/include/c++/11/bits/hashtable_policy.h:1219:25: error: no match for call to '(const std::hash<std::pair<int, int> >) (const std::pair<int, int>&)' 1219 | return _M_hash()(__k); | ~~~~~~~~~^~~~~