Language: C++

//pragma
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

#define YOU using
#define DONT namespace
#define SAY std

YOU DONT SAY;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ll,int> pli;
typedef pair<int,ll> pil;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<pll> vll;

#define REPP(i,a,b,d) for(int i=a;i<=b;i+=d)
#define REP(i,a,b) REPP(i,a,b,1)
#define REVV(i,a,b,d) for(int i=a;i>=b;i-=d)
#define REV(i,a,b) REVV(i,a,b,1)

#define FOR(i,a) for(int i=0; i<a; i++)
#define FORD(i,a) for(int i=(int)a-1; i>=0; i--)

#define mp make_pair

#define pb push_back
#define F first
#define S second

const int OO = 1e9;
const ll INF = 1e18;

const int irand(int lo,int hi){
    return ((double)rand()/(RAND_MAX + 1.0)) * (hi-lo+1) + lo;
}

const ll lrand(ll lo,ll hi){
    return ((double)rand()/(RAND_MAX + 1.0)) * (hi-lo+1) + lo;
}

#define getc getchar
template<typename T>
T getnum(){
    int sign = 1;
    T ret = 0;
    char c;

    do{
        c = getc();
    }while(c == ' ' || c == '\n');
    if(c == '-')sign = -1;
    else ret = c-'0';
    while(1){
        c = getc();
        if(c < '0' || c > '9')break;
        ret = 10*ret + c-'0';
    }
    return sign * ret;
}

inline void ini(int& x){
    x = getnum<int>();
}

inline void scani(int& x){
    scanf("%d",&x);
}

//end of macro

const int N = 2e5 + 5;

int n;
int x[N];
vii lst[N];

pair<ll,int> best[N];

unordered_set<pair<ll,int> >bests;

bool init = true;
void update(int now, int par, int src, ll dist){
    if(best[now].F <= dist + x[now])return;

    if(!init)bests.erase(mp(best[now].F, now));
    best[now] = mp(dist + x[now], src);
    bests.insert(mp(best[now].F, now));
    // printf("insert %d %d\n",best[now].F, now);

    FOR(i,lst[now].size()){
        int to = lst[now][i].F;
        if(to == par)continue;
        update(to, now, src, dist + lst[now][i].S);
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    #define endl '\n'
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(10);

    cin>>n;
    REP(i,1,n)cin>>x[i];
    REP(i,1,n-1){
        int a,b,c;
        cin>>a>>b>>c;
        lst[a].pb(mp(b,c));
        lst[b].pb(mp(a,c));
    }

    int root = 1;
    best[1] = mp(INF, OO);
    REP(i,2,n){
        if(x[i] < x[root])root = i;
        best[i] = mp(INF, OO);
    }

    ll ans = 0;
    update(root, -1, root, x[root]);
    init = false;

    REP(i,1,n-1){
        // printf("edge %d\n",i);
        int id;
        while(1){
            auto it = bests.begin();
            if(it->S == best[it->S].S){
                bests.erase(it);
            }else{
                id = it->S;
                bests.erase(it);
                break;
            }
        }
        // printf("match %d - %d\n",id, best[id].S);
        ans += best[id].F;
        update(id, -1, id, x[id]);
    }

    cout << ans << endl;

    return 0;
}

Compiler output:
a.cc:86:29: error: use of deleted function 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set() [with _Value = std::pair<long long int, int>; _Hash = std::hash<std::pair<long long int, int> >; _Pred = std::equal_to<std::pair<long long int, int> >; _Alloc = std::allocator<std::pair<long long int, int> >]'
   86 | unordered_set<pair<ll,int> >bests;
      |                             ^~~~~
In file included from /usr/include/c++/14/unordered_set:41,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:189,
                 from a.cc:5:
/usr/include/c++/14/bits/unordered_set.h:142:7: note: 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set() [with _Value = std::pair<long long int, int>; _Hash = std::hash<std::pair<long long int, int> >; _Pred = std::equal_to<std::pair<long long int, int> >; _Alloc = std::allocator<std::pair<long long int, int> >]' is implicitly deleted because the default definition would be ill-formed:
  142 |       unordered_set() = default;
      |       ^~~~~~~~~~~~~
/usr/include/c++/14/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<long long int, int>; _Value = std::pair<long long int, int>; _Alloc = std::allocator<std::pair<long long int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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++/14/bits/unordered_map.h:33,
                 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:
/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<long long int, int>; _Value = std::pair<long long int, int>; _Alloc = std::allocator<std::pair<long long int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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:
  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<long long int, int>; _Value = std::pair<long long int, int>; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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++/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<long long int, int>; _Value = std::pair<long long int, int>; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<long long int, int> >; _Hash = std::hash<std::pair<long long 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:
 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<long long int, int>; _Value = std::pair<long long int, int>; _ExtractKey = std::__detail::_Identity; _Hash = std::hash<std::pair<long long 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<long long 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<long long 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<long long 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<long long 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<long long 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<long long 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<long long int, int>; _Value = std::pair<long long int, int>; _ExtractKey = std::__detail::_Identity; _Hash = std::hash<std::pair<long long 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<long long 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<long long 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<long long int, int> >::~hash()'
/usr/include/c++/14/bits/functional_hash.h:102:12: note: 'std::hash<std::pair<long long 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<long long 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<long long int, int>, std::pair<long long int, int>, std::__detail::_Identity, std::hash<std::pair<long long int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()'
/usr/include/c++/14/bits/hashtable_policy.h:1306:12: note: 'std::__detail::_Hash_code_base<std::pair<long long int, int>, std::pair<long long int, int>, std::__detail::_Identity, std::hash<std::pair<long long 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:
 1306 |     struct _Hash_code_base
      |            ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/hashtable_policy.h:1306:12: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<long long int, int> >, true>::~_Hashtable_ebo_helper()'