Submission #624507

#	Time	Username	Problem	Language	Result	Execution time	Memory
624507		Hanksburger	Cities (BOI16_cities)	C++17	100 / 100	1858 ms	42860 KiB

cities

#include <bits/stdc++.h>
using namespace std;
vector<pair<long long, long long> > adj[100005];
priority_queue<pair<long long, long long> > pq;
long long dp[32][100005], a[5];
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    long long n, m, p;
    cin >> n >> p >> m;
    for (long long i=0; i<p; i++)
        cin >> a[i];
    for (long long i=0; i<m; i++)
    {
        long long u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
    for (long long i=0; i<(1<<p); i++)
        for (long long j=1; j<=n; j++)
            dp[i][j]=1e18;
    for (long long i=0; i<p; i++)
        dp[1<<i][a[i]]=0;
    for (long long i=1; i<(1<<p); i++)
    {
        for (long long j=0; j<p; j++)
            if (i&(1<<j))
                for (long long k=1; k<=n; k++)
                    dp[i][k]=min(dp[i][k], dp[i^(1<<j)][k]+dp[1<<j][k]);
        for (long long j=1; j<=n; j++)
            if (dp[i][j]<1e18)
                pq.push({-dp[i][j], j});
        while (!pq.empty())
        {
            long long d=pq.top().first, u=pq.top().second;
            pq.pop();
            if (dp[i][u]!=-d)
                continue;
            for (long long j=0; j<adj[u].size(); j++)
            {
                long long v=adj[u][j].first, w=adj[u][j].second;
                if (dp[i][u]+w<dp[i][v])
                {
                    dp[i][v]=dp[i][u]+w;
                    pq.push({-dp[i][v], v});
                }
            }
        }
    }
    long long ans=1e18;
    for (long long i=1; i<=n; i++)
        ans=min(ans, dp[(1<<p)-1][i]);
    cout << ans;
    return 0;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:42:34: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |             for (long long j=0; j<adj[u].size(); j++)
      |                                 ~^~~~~~~~~~~~~~

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