Submission #1105507

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105507		_callmelucian	Cities (BOI16_cities)	C++14	100 / 100	5513 ms	171416 KiB

cities

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<ll,int,int> tpl;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 1e5 + 5;
vector<pii> adj[mn];
ll dist[mn][1 << 5], gather[mn];
bool vis[mn][1 << 5];

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, k, m; cin >> n >> k >> m;
    for (int i = 1; i <= n; i++)
        for (int mask = 1; mask < (1 << k); mask++) dist[i][mask] = LLONG_MAX;
    priority_queue<tpl> pq;

    vector<int> fav(k);
    for (int i = 0; i < k; i++) {
        cin >> fav[i];
        dist[fav[i]][1 << i] = 0;
        pq.emplace(0, fav[i], 1 << i);
    }

    while (m--) {
        int a, b, c; cin >> a >> b >> c;
        adj[a].emplace_back(b, c);
        adj[b].emplace_back(a, c);
    }

    while (pq.size()) {
        ll d; int u, mask; tie(d, u, mask) = pq.top(); pq.pop();
        if (vis[u][mask]) continue;
        vis[u][mask] = 1;

        for (pii it : adj[u]) {
            int v, w; tie(v, w) = it;
            for (int supr = mask; supr < (1 << k); supr = (supr + 1) | mask) {
                if (dist[v][supr ^ mask] == LLONG_MAX) continue;
                if (dist[u][mask] + dist[v][supr ^ mask] + w < dist[v][supr]) {
                    dist[v][supr] = dist[u][mask] + dist[v][supr ^ mask] + w;
                    pq.emplace(-dist[v][supr], v, supr);
                }
            }
        }
    }

    ll ans = LLONG_MAX;
    for (int i : fav)
        ans = min(ans, dist[i][(1 << k) - 1]);
    cout << ans;

    return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26