Cod sursa(job #2025087)

Utilizator stelian2000Stelian Chichirim stelian2000 Data 21 septembrie 2017 20:39:12
Problema Ubuntzei Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.9 kb
#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

struct edge
{
    int nod,cost;
    bool operator <(const edge &aux) const
    {
        return cost>aux.cost;
    }
};

vector<edge> v[2010];
priority_queue<edge> q;
int d[2010],cost[2010][2010],v1[20],n,dp[32770][15];

void solve(int nod)
{
    for(int i=1;i<=n;i++) d[i]=2e9;
    q.push({nod,0});
    while(!q.empty())
    {
        int nod=q.top().nod,cost=q.top().cost;
        q.pop();
        if(d[nod]<cost) continue;
        for(int i=0;i<v[nod].size();i++)
        {
            int vec=v[nod][i].nod,c=v[nod][i].cost;
            if(d[vec]<=cost+c) continue;
            d[vec]=cost+c;
            q.push({vec,d[vec]});
        }
    }
    for(int i=1;i<=n;i++) cost[nod][i]=cost[i][nod]=d[i];
}

int main()
{
    freopen("ubuntzei.in","r",stdin);
    freopen("ubuntzei.out","w",stdout);
    int m,k,x,y,c;
    scanf("%d%d%d",&n,&m,&k);
    for(int i=0;i<k;i++) scanf("%d",&v1[i]);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x,&y,&c);
        v[x].push_back({y,c});
        v[y].push_back({x,c});
    }
    for(int i=0;i<k;i++) solve(v1[i]);
    solve(1);
    if(k==0) {printf("%d",cost[1][n]);return 0;}
    for(int mask=1;mask<(1<<k);mask++)
        for(int i=0;i<k;i++)
            dp[mask][i]=2e9;
    for(int i=0;i<k;i++) dp[(1<<i)][i]=cost[1][v1[i]];
    for(int mask=1;mask<(1<<k)-1;mask++)
        for(int i=0;i<k;i++)
        {
            int nod=v1[i];
            if(mask&(1<<i)) continue;
            for(int j=0;j<k;j++)
            {
                if(mask&(1<<j)==0) continue;
                int nod1=v1[j];
                dp[mask+(1<<i)][i]=min(dp[mask+(1<<i)][i],dp[mask][j]+cost[nod][nod1]);
            }
        }
    int sol=2e9;
    for(int i=0;i<k;i++)
        sol=min(sol,dp[(1<<k)-1][i]+cost[v1[i]][n]);
    printf("%d",sol);
    return 0;
}