Submission #956242

#	Time	Username	Problem	Language	Result	Execution time	Memory
956242		12345678	Cities (BOI16_cities)	C++17	100 / 100	2035 ms	49872 KiB

cities

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const int nx=1e5+5;

ll n, m, k, x, dp[33][nx], u, v, w, res=LLONG_MAX;
vector<pair<ll, ll>> d[nx];

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>k>>m;
    for (int i=1; i<(1<<k); i++) for (int j=1; j<=n; j++) dp[i][j]=1e18;
    for (int i=0; i<k; i++) cin>>x, dp[(1<<i)][x]=0;
    for (int i=0; i<m; i++) cin>>u>>v>>w, d[u].push_back({v, w}), d[v].push_back({u, w});
    for (int i=1; i<(1<<k); i++)
    {
        for (int j=1; j<=n; j++) for (int k=i; k>0; k=(k-1)&i) dp[i][j]=min(dp[i][j], dp[i^k][j]+dp[k][j]);
        priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> pq;
        for (int j=1; j<=n; j++) pq.push({dp[i][j], j});
        while (!pq.empty())
        {
            auto [w, u]=pq.top();
            pq.pop();
            for (auto [v, nw]:d[u]) if (w+nw<dp[i][v]) dp[i][v]=w+nw, pq.push({w+nw, v});
        }
    }
    for (int i=1; i<=n; i++) res=min(res, dp[(1<<k)-1][i]);
    cout<<res;
}

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