Submission #1005963

#	Time	Username	Problem	Language	Result	Execution time	Memory
1005963		serifefedartar	One-Way Streets (CEOI17_oneway)	C++17	Compilation error	0 ms	0 KiB

oneway

#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
typedef long long ll;
#define f first
#define s second
#define LOGN 20
const ll MOD = 1e9 + 7;
const ll MAXN = 1e5 + 100;
 
vector<vector<int>> graph, G, G2, G_rev;
int mark[MAXN], a[MAXN], b[MAXN], vis[MAXN], par[MAXN], sz[MAXN], ways[MAXN];
 
int find(int node) {
    if (node == par[node])
        return node;
    return par[node] = find(par[node]);
}
 
void unite(int a, int b) {
    a = find(a);
    b = find(b);
    if (a == b)
        return ;
    if (sz[b] > sz[a])
        swap(a, b);
    par[b] = a;
    sz[a] += sz[b];
}

void dfs(int node, int parent) {
    vis[node] = 1;
    for (auto u : graph[node]) {
        if (u != parent && vis[u] != 2) {
            G[node].push_back(u);
            G_rev[u].push_back(node);
        }
        if (!vis[u])
            dfs(u, node);
    }
    vis[node] = 2;
}
 
stack<int> nds;
void dfs2(int node) {
    vis[node] = true;
    for (auto u : G[node]) {
        if (vis[u] == 0)
            dfs2(u);
    }
    nds.push(node);
}
 
void dfs3(int node) {
    vis[node] = true;
    for (auto u : G_rev[node]) {
        if (vis[u])
            continue;
        unite(node, u);
        dfs3(u);
    }
}
 
unordered_map<pair<int,int>,int> mp;
void dfs4(int node, int parent) {
    vis[node] = true;
    for (auto u : G2[node]) {
        if (u == parent)
            continue;
        dfs4(u, node);
        mark[node] += mark[u];
        if (mark[u] > 0) { // edge : u -> node
            if (mp[{u, node}] == 0)
                ways[mp[{node, u}]] = 1;
            else
                ways[mp[{u, node}]] = 2;
        } else if (mark[u] < 0) { // edge : node -> u
            if (mp[{u, node}] == 0)
                ways[mp[{node, u}]] = 2;
            else
                ways[mp[{u, node}]] = 1;
        }
    }
}

int main() {
    fast
    int n, m, q;
    cin >> n >> m;
 
    for (int i = 1; i <= n; i++)
        par[i] = i, sz[i] = 1;
    graph = vector<vector<int>>(n+1, vector<int>());
    G = vector<vector<int>>(n+1, vector<int>());
    G2 = vector<vector<int>>(n+1, vector<int>());
    G_rev = vector<vector<int>>(n+1, vector<int>());
    for (int i = 1; i <= m; i++) {
        cin >> a[i] >> b[i];
        graph[a[i]].push_back(b[i]);
        graph[b[i]].push_back(a[i]);
    }
    for (int i = 1; i <= n; i++) {
        if (!vis[i])
            dfs(i, i);
    }
    for (int i = 1; i <= n; i++)
        vis[i] = 0;
    for (int i = 1; i <= n; i++) {
        if (!vis[i])
            dfs2(i);
    }
    for (int i = 1; i <= n; i++)
        vis[i] = 0;
    while (nds.size()) {
        int node = nds.top();
        nds.pop();
        if (!vis[node])
            dfs3(node);
    }
    for (int i = 1; i <= m; i++) {
        if (find(a[i]) != find(b[i]))
            mp[{find(a[i]), find(b[i])}] = i;
    }
 
    for (int i = 1; i <= m; i++) {
        if (find(a[i]) == find(b[i]))
            ways[i] = -1;
        else {
            G2[find(a[i])].push_back(find(b[i]));
            G2[find(b[i])].push_back(find(a[i]));
        }
    }

    cin >> q;
    while (q--) {
        int a, b;
        cin >> a >> b;
        a = find(a);
        b = find(b);
        if (a == b)
            continue;
 
        mark[b] -= 1;
        mark[a] += 1;
    }

    for (int i = 1; i <= n; i++)
        vis[i] = false;
    for (int i = 1; i <= n; i++) {
        if (!vis[find(i)])
            dfs4(find(i), find(i));
    }
    
    for (int i = 1; i <= m; i++) {
        if (ways[i] == 1)
            cout << "L";
        else if (ways[i] == 2)
            cout << "R";
        else
            cout << "B";
    }
    cout << "\n";
}

Compilation message (stderr)

oneway.cpp:65:34: 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> >]'
   65 | unordered_map<pair<int,int>,int> mp;
      |                                  ^~
In file included from /usr/include/c++/10/unordered_map:47,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/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++/10/bits/unordered_map.h:141:7: error: use of deleted function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _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> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = 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++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/bits/hashtable.h:451:7: note: 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _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> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = 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:
  451 |       _Hashtable() = default;
      |       ^~~~~~~~~~
/usr/include/c++/10/bits/hashtable.h:451:7: error: use of deleted function 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _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> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, false, true>]'
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1791:5: note: 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _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> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, false, true>]' is implicitly deleted because the default definition would be ill-formed:
 1791 |     _Hashtable_base() = default;
      |     ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1791:5: error: use of deleted function 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::_Hash_code_base() [with _Key = std::pair<int, int>; _Value = std::pair<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing]'
/usr/include/c++/10/bits/hashtable_policy.h:1368:7: note: 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::_Hash_code_base() [with _Key = std::pair<int, int>; _Value = std::pair<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing]' is implicitly deleted because the default definition would be ill-formed:
 1368 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1368:7: error: use of deleted function '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++/10/bits/hashtable_policy.h:1112:7: note: 'std::__detail::_Hashtable_ebo_helper<_Nm, _Tp, true>::_Hashtable_ebo_helper() [with int _Nm = 1; _Tp = std::hash<std::pair<int, int> >]' is implicitly deleted because the default definition would be ill-formed:
 1112 |       _Hashtable_ebo_helper() = default;
      |       ^~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1112:7: error: use of deleted function 'std::hash<std::pair<int, int> >::hash()'
In file included from /usr/include/c++/10/string_view:42,
                 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 oneway.cpp:1:
/usr/include/c++/10/bits/functional_hash.h:101:12: note: 'std::hash<std::pair<int, int> >::hash()' is implicitly deleted because the default definition would be ill-formed:
  101 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/10/bits/functional_hash.h:101:12: error: no matching function for call to 'std::__hash_enum<std::pair<int, int>, false>::__hash_enum()'
/usr/include/c++/10/bits/functional_hash.h:82:7: note: candidate: 'std::__hash_enum<_Tp, <anonymous> >::__hash_enum(std::__hash_enum<_Tp, <anonymous> >&&) [with _Tp = std::pair<int, int>; bool <anonymous> = false]'
   82 |       __hash_enum(__hash_enum&&);
      |       ^~~~~~~~~~~
/usr/include/c++/10/bits/functional_hash.h:82:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/10/bits/functional_hash.h:101:12: error: 'std::__hash_enum<_Tp, <anonymous> >::~__hash_enum() [with _Tp = std::pair<int, int>; bool <anonymous> = false]' is private within this context
  101 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/10/bits/functional_hash.h:83:7: note: declared private here
   83 |       ~__hash_enum();
      |       ^
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1112:7: error: use of deleted function 'std::hash<std::pair<int, int> >::~hash()'
 1112 |       _Hashtable_ebo_helper() = default;
      |       ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/string_view:42,
                 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 oneway.cpp:1:
/usr/include/c++/10/bits/functional_hash.h:101:12: note: 'std::hash<std::pair<int, int> >::~hash()' is implicitly deleted because the default definition would be ill-formed:
  101 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/10/bits/functional_hash.h:101:12: 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++/10/bits/functional_hash.h:83:7: note: declared private here
   83 |       ~__hash_enum();
      |       ^
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1368:7: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()'
 1368 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1109:12: 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:
 1109 |     struct _Hashtable_ebo_helper<_Nm, _Tp, true>
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1109:12: error: use of deleted function 'std::hash<std::pair<int, int> >::~hash()'
/usr/include/c++/10/bits/hashtable_policy.h:1791:5: 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()'
 1791 |     _Hashtable_base() = default;
      |     ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1341:12: 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:
 1341 |     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1342 |       _Default_ranged_hash, true>
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1341:12: 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++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/bits/hashtable.h:451:7: 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()'
  451 |       _Hashtable() = default;
      |       ^~~~~~~~~~
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1725:10: 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:
 1725 |   struct _Hashtable_base
      |          ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1725:10: 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()'
/usr/include/c++/10/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::__hash_code std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::_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; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::__hash_code = long unsigned int]':
/usr/include/c++/10/bits/hashtable_policy.h:734:45:   required from 'std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::mapped_type& std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::operator[](std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::key_type&&) [with _Key = std::pair<int, int>; _Pair = std::pair<const std::pair<int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; _Equal = std::equal_to<std::pair<int, int> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, false, true>; std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::mapped_type = int; std::__detail::_Map_base<_Key, _Pair, _Alloc, std::__detail::_Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::key_type = std::pair<int, int>]'
/usr/include/c++/10/bits/unordered_map.h:988:20:   required from 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::mapped_type& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::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>::mapped_type = int; std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::key_type = std::pair<int, int>]'
oneway.cpp:74:29:   required from here
/usr/include/c++/10/bits/hashtable_policy.h:1377:16: error: static assertion failed: hash function must be invocable with an argument of key type
 1377 |  static_assert(__is_invocable<const _H1&, const _Key&>{},
      |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1379:16: error: no match for call to '(const std::hash<std::pair<int, int> >) (const std::pair<int, int>&)'
 1379 |  return _M_h1()(__k);
      |         ~~~~~~~^~~~~
In file included from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from oneway.cpp:1:
/usr/include/c++/10/bits/hashtable.h: In instantiation of 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _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> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, false, true>]':
/usr/include/c++/10/bits/unordered_map.h:102:11:   required from here
/usr/include/c++/10/bits/hashtable.h:1389:5: 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()'
 1389 |     }
      |     ^