Submission #1111224

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111224		f0rizen	Cities (BOI16_cities)	C++17	74 / 100	6070 ms	170644 KiB

cities

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
const int inf = 1e9 + 7;
const ll infll = 1e18;

template<typename T>
istream &operator>>(istream &is, vector<T> &a) {
    for (auto &i : a) {
        is >> i;
    }
    return is;
}

int32_t main() {
#ifdef LOCAL
    freopen("/tmp/input.txt", "r", stdin);
#else
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
#endif
    int n, k, m;
    cin >> n >> k >> m;
    vector<int> a(k);
    cin >> a;
    for (auto &i : a) {
        --i;
    }
    vector<vector<pair<int, int>>> g(n);
    for (int i = 0; i < m; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        --u, --v;
        g[u].push_back({v, w});
        g[v].push_back({u, w});
    }
    vector<vector<ll>> dp(1 << k, vector<ll>(n, infll));
    using pii = pair<ll, pair<int, int>>;
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    for (int i = 0; i < k; ++i) {
        dp[1 << i][a[i]] = 0;
        pq.push({dp[1 << i][a[i]], {1 << i, a[i]}});
    }
    while (!pq.empty()) {
        auto [_, a] = pq.top();
        pq.pop();
        auto [mask, v] = a;
        if (_ > dp[mask][v]) {
            continue;
        }
        for (auto [u, w] : g[v]) {
            if (dp[mask][u] > dp[mask][v] + w) {
                dp[mask][u] = dp[mask][v] + w;
                pq.push({dp[mask][u], {mask, u}});
            }
            int mm = ((1 << k) - 1) ^ mask;
            for (int s = mm; s > 0; s = (s - 1) & mm) {
                if (dp[mask | s][u] > dp[mask][v] + dp[s][u] + w) {
                    dp[mask | s][u] = dp[mask][v] + dp[s][u] + w;
                    pq.push({dp[mask | s][u], {mask | s, u}});
                }
            }
        }
    }
    ll ans = infll;
    for (int i = 0; i < n; ++i) {
        ans = min(ans, dp[(1 << k) - 1][i]);
    }
    cout << ans << "\n";
    return 0;
}

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