Cod sursa(job #1911417)

Utilizator TibiraducanuTiberiu Raducanu Tibiraducanu Data 7 martie 2017 20:25:00
Problema Ubuntzei Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.95 kb
#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

const int N=2005,K=20;
const long long Inf=(1ll<<60);
int n,m,k,a,b,c,v[K],mat[K][N],pos[N];
bool check[N],sem;
long long dist[N],d[(1<<K)][K];

struct ii{
    long long dist;
    int nod;
};
struct ij{
    int dist,nod;
};
struct cmp{
    bool operator() (ii &a,ii &b){
        return a.dist>b.dist;
    }
};
vector <ij> G[N];
priority_queue< ii, vector<ii>, cmp > pq;

void Dijkstra(int t){
    int i,x,y;
    long long d;
    for(i=1;i<=n;i++) dist[i]=Inf;
    dist[t]=0;
    pq.push({0ll,t});

    while(!pq.empty()){
        d=pq.top().dist;
        x=pq.top().nod;
        pq.pop();
        if(d>dist[x]) continue;

        for(i=0;i<(int)G[x].size();i++){
            y=G[x][i].nod;
            d=G[x][i].dist;

            if(dist[x]+d<dist[y]){
                dist[y]=dist[x]+d;
                pq.push({dist[y],y});
            }
        }
    }
}



int main(){
    freopen("ubuntzei.in","r",stdin);
    freopen("ubuntzei.out","w",stdout);

    int i,j;
    scanf("%d%d",&n,&m);
    scanf("%d",&k);
    for(i=0;i<k;i++){
        scanf("%d",&v[i]);
        check[v[i]]=1;
        pos[v[i]]=i;
    }

    v[k]=n, check[n]=1, pos[n]=k, k++;

    for(i=1;i<=m;i++){
        scanf("%d%d%d",&a,&b,&c);
        G[a].push_back({c,b});
        G[b].push_back({c,a});
    }

    for(i=0;i<k;i++){
        Dijkstra(v[i]);
        for(j=1;j<=n;j++){
            mat[i][j]=dist[j];
        }
    }

    int S=(1<<k)-1;
    for(i=0;i<=S;i++)
        for(j=0;j<k;j++)
            d[i][j]=Inf;

    for(i=0;i<k;i++)
        d[(1<<i)][i]=1ll*mat[i][1];

    for(i=1;i<=S;i++)
        for(j=0;j<k;j++)
            if(i&(1<<j))
                for(int t=0;t<k;t++)
                    if(i&(1<<t))
                        d[i][j]=min(d[i][j],d[i^(1<<j)][t]+mat[t][v[j]]);

    printf("%lld\n",d[S][pos[n]]);

    return 0;
}