Language: C++

#include <bits/stdc++.h>

#define LL long long
#define VI vector<int>
#define VB vector<bool>
#define VL vector<long long>
#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT(n) (1LL<<(n))
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());
#define EPS 1e-14

const std::string YES = "YES";
const std::string Yes = "Yes";
const std::string NO = "NO";
const std::string No = "No";

using namespace std;

/**
 * startからすべての頂点への最小距離を求める O(|E| log |V|)
 * @param start
 * @param graph[node] = [(to1, cost1), (to2, cost2), ...]
 * @return
 */
vector<int> dijkstra(int start, vector<vector<int>> graph) {
    unsigned long n = graph.size();
    priority_queue<pair<int, int>> que; //[(最短距離, node番号)]
    que.push({0, start});

    vector<int> prev_list(n, -1);
    vector<int> dist_list(n, INT_MAX);
    dist_list[start] = 0;

    while (!que.empty()) {
        int now_dist = que.top().first;
        int from = que.top().second;
        que.pop();

        if (dist_list[from] < now_dist) {
            continue;
        }
        for (int to : graph[from]) {
            int dist = 1;
            int new_dist = now_dist + dist;

            if (dist_list[to] > new_dist) {
                prev_list[to] = from;
                dist_list[to] = new_dist;
                que.push({new_dist, to});
            }
        }
    }

    return dist_list;
}

void dfs(pair<int, int> &start, vector<int> &route, vector<vector<bool>> &used, unordered_map<pair<int, int>, vector<pair<int, int>>> &graph) {
    FOE(p, graph[start]) {
        if (used[p.first][p.second]) { continue; }
        used[p.first][p.second] = true;
        route.emplace_back(p.first);

        dfs(p, route, used, graph);
    }

}

int solve(int N, int M, const vector<int> &P, vector<int> &Q, vector<int> &C) {

    unordered_map<pair<int, int>, vector<pair<int, int>>> graph;    // (駅, 会社)から到達できる(駅, 会社)のリスト
    FOR(i, 0, P.size()) {
        graph[make_pair(P[i], C[i])].emplace_back(make_pair(Q[i], C[i]));
        graph[make_pair(Q[i], C[i])].emplace_back(make_pair(P[i], C[i]));
    }

    vector<vector<bool>> used(N + 1, vector<bool>(N + 1, false));

    vector<vector<int>> station_route_graph(N * 3);
    int route_id = N + 2;
    FOE(&p, graph) {
        auto a = p.first;
        if (used[a.first][a.second]) {
            continue;
        }
        vector<int> route = {a.first};
        used[a.first][a.second] = true;
        dfs(a, route, used, graph);

        FOE(station, route) {
            station_route_graph[station].push_back(route_id);
            station_route_graph[route_id].push_back(station);
        }
        route_id++;
    }

    auto dist_list = dijkstra(1, station_route_graph);
    int ans = dist_list[N];
    return ans == INT_MAX ? -1 : ans / 2;
}


int main() {
    int N, M;
    cin >> N >> M;

    vector<int> P(M), Q(M), C(M);
    FOR(i, 0, M) {
        cin >> P[i] >> Q[i] >> C[i];
    }

    cout << solve(N, M, P, Q, C) << endl;

    return 0;
}


Compiler output:
a.cc: In function 'int solve(int, int, const std::vector<int>&, std::vector<int>&, std::vector<int>&)':
a.cc:79:59: error: use of deleted function 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map() [with _Key = std::pair<int, int>; _Tp = std::vector<std::pair<int, int>, std::allocator<std::pair<int, 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > > > >]'
   79 |     unordered_map<pair<int, int>, vector<pair<int, int>>> graph;    // (駅, 会社)から到達できる(駅, 会社)のリスト
      |                                                           ^~~~~
In file included from /usr/include/c++/14/unordered_map:41,
                 from /usr/include/c++/14/functional:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/unordered_map.h:148:7: note: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map() [with _Key = std::pair<int, int>; _Tp = std::vector<std::pair<int, int>, std::allocator<std::pair<int, 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > > > >]' is implicitly deleted because the default definition would be ill-formed:
  148 |       unordered_map() = default;
      |       ^~~~~~~~~~~~~
/usr/include/c++/14/bits/unordered_map.h: At global scope:
/usr/include/c++/14/bits/unordered_map.h:148:7: 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > > >; _Alloc = std::allocator<std::pair<const std::pair<int, int>, std::vector<std::pair<int, int>, std::allocator<std::pair<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++/14/bits/unordered_map.h:33:
/usr/include/c++/14/bits/hashtable.h:539:7: 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > > >; _Alloc = std::allocator<std::pair<const std::pair<int, int>, std::vector<std::pair<int, int>, std::allocator<std::pair<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:
  539 |       _Hashtable() = default;
      |       ^~~~~~~~~~
/usr/include/c++/14/bits/hashtable.h:539:7: 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<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++/14/bits/hashtable.h:35:
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<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:
 1731 |       _Hashtable_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<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++/14/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++/14/bits/hashtable_policy.h:1328:7:   required from here
 1328 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1245:49: error: use of deleted function 'std::hash<std::pair<int, int> >::hash()'
 1245 |       _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { }
      |                                                 ^~~~~
In file included from /usr/include/c++/14/string_view:50,
                 from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/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++/14/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++/14/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++/14/bits/functional_hash.h:83:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/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++/14/bits/functional_hash.h:84:7: note: declared private here
   84 |       ~__hash_enum();
      |       ^
/usr/include/c++/14/bits/hashtable_policy.h:1245:49: note: use '-fdiagnostics-all-candidates' to display considered candidates
 1245 |       _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { }
      |                                                 ^~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1328:7: 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>, std::vector<std::pair<int, int>, std::allocator<std::pair<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:
 1328 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1328:7: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()'
/usr/include/c++/14/bits/hashtable_policy.h:1242:12: 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:
 1242 |     struct _Hashtable_ebo_helper<_Nm, _Tp, true>
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1242:12: error: use of deleted function 'std::hash<std::pair<int, int> >::~hash()'
/usr/include/c++/14/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++/14/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++/14/bits/functional_hash.h:84:7: note: declared private here
   84 |       ~__hash_enum();
      |       ^
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: note: use '-fdiagnostics-all-candidates' to display considered candidates
 1731 |       _Hashtable_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1731:7: error: use of deleted function 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<const std::pair<int, int>, std::vector<std::pair<int, int>, std