Submission #1243377

#	Time	Username	Problem	Language	Result	Execution time	Memory
1243377		chikien2009	Cities (BOI16_cities)	C++20	100 / 100	1101 ms	35788 KiB

cities

#include <bits/stdc++.h>

using namespace std;

void setup()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int n, k, m, v[5], a, b;
long long f[1 << 5][100000], c;
vector<pair<int, int>> g[100000];
priority_queue<pair<long long, int>> pq;

int main()
{
    setup();

    cin >> n >> k >> m;
    for (int i = 0; i < k; ++i)
    {
        cin >> v[i];
        v[i]--;
    }
    while (m--)
    {
        cin >> a >> b >> c;
        g[a - 1].push_back({b - 1, c});
        g[b - 1].push_back({a - 1, c});
    }
    for (int i = 1; i < (1 << k); ++i)
    {
        fill_n(f[i], n, 1e18);
        for (int j = 0; j < k; ++j)
        {
            f[1 << j][v[j]] = 0;
        }
        for (int j = 0; j < n; ++j)
        {
            for (int h = 0; h < i; ++h)
            {
                if ((i & h) == h)
                {
                    f[i][j] = min(f[i][j], f[h][j] + f[i ^ h][j]);
                }
            }
            if (f[i][j] < 1e18)
            {
                pq.push({-f[i][j], j});
            }
        }
        while (!pq.empty())
        {
            c = -pq.top().first;
            a = pq.top().second;
            pq.pop();
            if (c != f[i][a])
            {
                continue;
            }
            for (auto & j : g[a])
            {
                if (f[i][j.first] > f[i][a] + j.second)
                {
                    f[i][j.first] = f[i][a] + j.second;
                    pq.push({-f[i][j.first], j.first});
                }
            }
        }
    }
    c = 1e18;
    for (int i = 0; i < n; ++i)
    {
        c = min(c, f[(1 << k) - 1][i]);
    }
    cout << c;
    return 0;
}

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