Submission #1198662

#	Time	Username	Problem	Language	Result	Execution time	Memory
1198662		akusik	Cities (BOI16_cities)	C++20	0 / 100	67 ms	15428 KiB

cities

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

const ll INF = 2e17, MAXN = 1e5 + 1, mod = 1e9 + 7;

vector<pair<int, ll>> g[MAXN];
vector<int> imp;

vector<ll> dejkstra(int v, int n) {
    vector<ll> dist(n, INF);
    dist[v] = 0;
    set<pair<ll, int>> q;
    q.insert({ 0, v });
    while (!q.empty()) {
        int cur = (*q.begin()).second;
        q.erase(q.begin());
        for (auto& [to, c] : g[v]) {
            if (dist[to] > dist[v] + c) {
                dist[to] = dist[v] + c;
                q.insert({ dist[to], to });
            }
        }
    }
    return dist;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, k, m;
    cin >> n >> k >> m;
    imp.resize(k);
    for (int i = 0; i < k; ++i) {
        cin >> imp[i];
        imp[i]--;
    }
    for (int i = 0; i < m; ++i) {
        int a, b, c;
        cin >> a >> b >> c;
        --a, --b;
        g[a].push_back({ b, c });
        g[b].push_back({ a, c });
    }
    if (k == 2 || k == 3) {
        vector<vector<ll>> dist(k);
        for (int i = 0; i < k; ++i) {
            dist[i] = dejkstra(imp[i], n);
        }
        ll ans = INF;
        for (int i = 0; i < n; ++i) {
            ll cur = 0;
            for (auto& x : dist) {
                cur += x[i];
            }
            ans = min(ans, cur);
        }
        cout << ans << '\n';
    }
}

• Subtask 1: 0 / 22
• Subtask 2: 0 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 26