Cod sursa(job #584951)

Utilizator eudanipEugenie Daniel Posdarascu eudanip Data 27 aprilie 2011 13:58:48
Problema Ubuntzei Scor 15
Compilator cpp Status done
Runda Arhiva de probleme Marime 2.27 kb
#include<stdio.h>
#include<vector>
#include<set>
using namespace std;

#define minim(a,b) (a<b ? a : b)
#define INF 2000000006
#define pb push_back
#define NMAX 2010

vector<int> v[NMAX],cost[NMAX];
int n,m,k,dist[NMAX],d[20][NMAX];
int casa[20],bst[100005][20],sol;
set<int> myset;

class cmp
{
public:
    bool operator()(const int& a,const int& b)
    {
        return dist[a]<dist[b] ||
                (dist[a]==dist[b] && a<b);
    }
};

void dijkstra(int ind)
{
    int i,j,p,lim,vec;
    myset.clear();
    for(i=1;i<=n;i++)
        dist[i]=INF;
    dist[casa[ind]]=0;
    myset.insert(casa[ind]);
    for(i=1;i<=n;i++)
    {
        if(!myset.size())
            break;
        p=*myset.begin();
        myset.erase(myset.begin());
        lim=v[p].size();
        for(j=0;j<lim;j++)
        {
            vec=v[p][j];
            if(dist[p]+cost[p][j]<dist[vec])
            {
                myset.erase(vec);
                dist[vec]=dist[p]+cost[p][j];
                myset.insert(vec);
            }
        }
    }
    for(i=1;i<=n;i++)
        d[ind][i]=dist[i];
}

int main ()
{
    int i,j,t,a,b,c,cf;
    
    freopen("ubuntzei.in","r",stdin);
    freopen("ubuntzei.out","w",stdout);
    scanf("%d%d%d",&n,&m,&k);
    for(i=1;i<=k;i++)
        scanf("%d",&casa[i]);
    casa[++k]=1;
    for(i=1;i<=m;i++)
    {
        scanf("%d%d%d",&a,&b,&c);
        v[a].pb(b);
        cost[a].pb(c);

        v[b].pb(a);
        cost[b].pb(c);
    }

    for(i=1;i<=k;i++)
        dijkstra(i);
    k--;
    if(!k)
    {
        printf("%d\n",d[1][n]);
        return 0;
    }
    for(i=0;i<(1<<k);i++)
        for(j=1;j<=k;j++)
            bst[i][j]=INF;
    for(i=1;i<=k;i++)
        bst[(1<<(i-1))][i]=d[k+1][casa[i]];
    for(i=1;i<(1<<k);i++)
        for(j=1;j<=k;j++)
            if(bst[i][j]!=INF)
                for(t=1;t<=k;t++)
                    if(!(i&(1<<(t-1))))
                    {
                        cf=i+(1<<(t-1));
                        bst[cf][t]=minim(bst[cf][t],
                            bst[i][j]+d[j][casa[t]]);
                    }
    sol=INF;
    for(i=1;i<=k;i++)
        sol=minim(sol,bst[(1<<k)-1][i]+d[i][n]);
    printf("%d\n",sol);
    return 0;
}