Cod sursa(job #2618220)

Utilizator loraclorac lorac lorac Data 23 mai 2020 21:06:11
Problema Ubuntzei Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.9 kb
#include <fstream>
#include <vector>
#include <set>
using namespace std;
ifstream cin("ubuntzei.in");
ofstream cout("ubuntzei.out");
const int lim=2005,inf=2e9+7,doi15=32768+5;
int c[lim],dist[17][lim],dp[17][doi15];
vector<pair<int,int> > vec[lim];
set<pair<int,int> > s;
vector<int> sel;
int n,m,k,x,y,z;
void dijkstra(int ind)
{
    for(int i=1;i<=n;++i)
        dist[ind][i]=inf;
    dist[ind][c[ind]]=0;
    s.insert({0,c[ind]});
    while(!s.empty())
    {
        int t=(*(s.begin())).first;
        int x=(*(s.begin())).second;
        s.erase(s.begin());
        for(auto y:vec[x])
        if(dist[ind][y.first]>t+y.second)
        {
            if(dist[ind][y.first]!=inf)
                s.erase(s.find({dist[ind][y.first],y.first}));
            dist[ind][y.first]=t+y.second;
            s.insert({dist[ind][y.first],y.first});
        }
    }
}
int main()
{
    cin>>n>>m>>k;
    for(int i=1;i<=k;++i)
        cin>>c[i];
    for(int i=1;i<=m;++i)
    {
        cin>>x>>y>>z;
        vec[x].push_back({y,z});
        vec[y].push_back({x,z});
    }
    c[0]=1;
    for(int i=0;i<=k;++i)
        dijkstra(i);
    if(k==0)
    {
        cout<<dist[0][n]<<'\n';
        return 0;
    }
    int supp=(1<<k)-1;
    for(int kk=1;kk<=supp;++kk)
    {
        int mask=kk;
        sel.clear();
        for(int i=1;i<=k;++i)
        {
            if(mask%2) sel.push_back(i);
            mask/=2;
        }
        if(sel.size()==1)
        {
            dp[sel[0]][kk]=dist[0][c[sel[0]]];
            continue;
        }
        for(auto i:sel)
        {
            int elim=kk-(1<<(i-1));
            dp[i][kk]=inf;
            for(auto j:sel)
            if(j!=i) dp[i][kk]=min(dp[i][kk],dp[j][elim]+dist[j][c[i]]);
        }
    }
    int ans=inf;
    for(int i=1;i<=k;++i)
        ans=min(ans,dp[i][supp]+dist[i][n]);
    cout<<ans<<'\n';
    return 0;
}