Submission #1245848

#	Time	Username	Problem	Language	Result	Execution time	Memory
1245848		flaming_top1	Cities (BOI16_cities)	C++20	100 / 100	2246 ms	48568 KiB

cities

#include <bits/stdc++.h>

#define SPED                                                                                                           \
    ios_base::sync_with_stdio(false);                                                                                  \
    cin.tie(0);                                                                                                        \
    cout.tie(0);

#define endl "\n"
#define fi first
#define se second
#define lint long long
#define fami signed
#define lore main
#define freefire freopen

const lint INF = 1e15;

using namespace std;

int n, k, m;
vector<pair<int, lint>> adj[100005];
lint dp[100005][(1 << 5) + 5];

fami lore()
{
    memset(dp, 0x1f, sizeof dp);
    SPED;
    cin >> n >> k >> m;
    for (int i = 0; i < k; i++)
    {
        int u;
        cin >> u;
        dp[u][1 << i] = 0;
    }
    for (int i = 1; i <= m; i++)
    {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].emplace_back(v, w);
        adj[v].emplace_back(u, w);
    }
    for (int mask = 1; mask < (1 << k); mask++)
    {
        priority_queue<pair<lint, lint>, vector<pair<lint, lint>>, greater<pair<lint, lint>>> pq;

        for (int i = 1; i <= n; i++)
        {
            for (int sub = mask; sub > 0; sub = (sub - 1) & mask)
            {
                dp[i][mask] = min(dp[i][mask], dp[i][sub] + dp[i][mask ^ sub]);
            }
            if (dp[i][mask] < INF)
                pq.emplace(dp[i][mask], i);
        }

        while (!pq.empty())
        {
            auto [cur, u] = pq.top();
            pq.pop();
            if (cur > dp[u][mask])
                continue;
            for (auto [v, w] : adj[u])
            {
                if (dp[v][mask] > cur + w)
                {
                    dp[v][mask] = cur + w;
                    pq.emplace(dp[v][mask], v);
                }
            }
        }
    }
    lint ans = INF;
    for (int i = 1; i <= n; i++)
        ans = min(ans, dp[i][(1 << k) - 1]);
    cout << ans;
}
// Let your soul wander where dreams are born.

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