제출 #1194185

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1194185		LucaIlie	Cities (BOI16_cities)	C++17	100 / 100	615 ms	27928 KiB

cities

#include <bits/stdc++.h>

using namespace std;

struct edge {
    int u, v, c;
    int other(int w) {
        return u ^ v ^ w;
    }
};

struct infopq {
    int v;
    long long d;
    bool operator<(const infopq &x) const {
        return d > x.d;
    }
};

const int MAX_N = 1e5;
const int MAX_M = 2e5;
const int MAX_K = 5;
const long long INF = 1e18;
int n;
edge edges[MAX_M];
vector<int> adj[MAX_N + 1];
int cities[MAX_K];
long long dist[(1 << (MAX_K - 1))][MAX_N + 1];
bool vis[MAX_N + 1];

void dijkstra(long long dist[]) {
    priority_queue<infopq> pq;
    for (int v = 1; v <= n; v++) {
        vis[v] = false;
        pq.push({v, dist[v]});
    }

    while (!pq.empty()) {
        auto u = pq.top().v;
        pq.pop();

        if (vis[u])
            continue;
        vis[u] = true;

        for (int e: adj[u]) {
            int v = edges[e].other(u), c = edges[e].c;
            if (dist[u] + c < dist[v]) {
                dist[v] = dist[u] + c;
                pq.push({v, dist[v]});
            }
        }
    }
}

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

    int k, m;

    cin >> n >> k >> m;
    for (int i = 0; i < k; i++)
        cin >> cities[i];

    for (int e = 0; e < m; e++) {
        cin >> edges[e].u >> edges[e].v >> edges[e].c;
        adj[edges[e].u].push_back(e);
        adj[edges[e].v].push_back(e);
    }

    for (int mask = 1; mask < (1 << (k - 1)); mask++) {
        for (int v = 1; v <= n; v++)
            dist[mask][v] = INF;
    }

    for (int i = 0; i < k - 1; i++)
        dist[(1 << i)][cities[i]] = 0;
    for (int mask = 1; mask < (1 << (k - 1)); mask++) {
        dijkstra(dist[mask]);
        for (int mask2 = 1; mask2 < mask; mask2++) {
            for (int v = 1; v <= n; v++)
                dist[mask | mask2][v] = min(dist[mask | mask2][v], dist[mask][v] + dist[mask2][v]);
        }
        /* printf("MASK %d\n", mask); */
        /* for (int v = 1; v <= n; v++) */
        /*     printf("%lld ", dist[mask][v]); */
        /* printf("\n"); */
    }

    cout << dist[(1 << (k - 1)) - 1][cities[k - 1]] << "\n";

    return 0;
}

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