Submission #1075357

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075357		vjudge1	Cities (BOI16_cities)	C++14	100 / 100	2056 ms	52164 KiB

cities

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n,k,m;
    cin >> n >> k >> m;
    vector<vector<pair<int,int>>> graph(n+1);
    int DP[n+1][1<<k];
    bool vis[n+1][1<<k];
    memset(vis,false,sizeof(vis));
    vector<int> impo(k);
    for(int i=0;i<k;i++){
        cin >> impo[i];
    }
    for(int i=0;i<m;i++){
        int a,b,c;
        cin >> a >> b >> c;
        graph[a].push_back({b,c});
        graph[b].push_back({a,c});
    }
    for(int mask=1;mask<(1<<k);mask++){
        priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;
        if(!(mask&(mask-1))){
            for(int u=1;u<=n;u++){
                DP[u][mask]=1e18;
            }
            for(int i=0;i<k;i++){
                if(mask&(1<<i)){
                    DP[impo[i]][mask]=0;
                    pq.push({0,impo[i]});
                }
            }
        }
        else{
            for(int u=1;u<=n;u++){
                DP[u][mask]=1e18;
                for(int s=((mask-1)&mask);s;s=((s-1)&mask)){
                    DP[u][mask]=min(DP[u][mask],DP[u][s]+DP[u][mask^s]);
                }
                pq.push({DP[u][mask],u});
            }
        }
        while(!pq.empty()){
            int u=pq.top().second,weight=pq.top().first;
            pq.pop();
            if(weight>DP[u][mask]||vis[u][mask]){
                continue;
            }
            vis[u][mask]=true;
            for(pair<int,int> x:graph[u]){
                int v=x.first;
                int dist=DP[u][mask]+x.second;
                if(dist<DP[v][mask]){
                    DP[v][mask]=dist;
                    pq.push({dist,v});
                }
            }
        }
    }
    /*for(int mask=1;mask<(1<<k);mask++){
        cout << mask << ": " << endl;
        for(int u=1;u<=n;u++){
            cout << DP[u][mask] << ' ';
        }
        cout << endl;
    }*/
    int ans=1e18;
    for(int u=1;u<=n;u++){
        ans=min(ans,DP[u][(1<<k)-1]);
    }
    cout << ans;
}

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