HDU 2680 Choose the best route

struct edge{
    int to;
    int cost;
    int next;
}adj[20010];
int head[1010],num;

void addedge(int from, int to, int cost){
    adj[num].to = to;
    adj[num].cost = cost;
    adj[num].next = head[from];
    head[from] = num++;
}

int dis[1010],vis[1010],enter[1010];

bool SPFA(int scr){
    for(int i=1; i<=V; i++){
        dis[i] = 1e9;
        vis[i] = 0;
        enter[i] = 0;
    }
    vis[scr] = 1;
    dis[scr] = 0;
    enter[scr] = 1;
    queue <int> Q;
    Q.push(scr);
    while(!Q.empty()){
        int tmp = Q.front();
        Q.pop();
        vis[tmp] = 0;
        for(int i=head[tmp]; i!=-1; i=adj[i].next){
            if(dis[adj[i].to] > dis[tmp] + adj[i].cost){
                dis[adj[i].to] = dis[tmp] + adj[i].cost;
                if(!vis[adj[i].to]){
                    vis[adj[i].to] = 1;
                    enter[adj[i].to]++;
                    if(enter[adj[i].to] >= V)
                        return false;
                    Q.push(adj[i].to);
                }
            }
        }
    }
    return true;
}

int main(){
//    freopen("in.txt", "r", stdin);
    while(scanf("%d%d%d",&V,&E,&key) == 3){
        memset(head, -1, sizeof(head));
        num = 0;
        for(int i=0; i<E; i++){
            int from, to, cost;
            scanf("%d%d%d",&from,&to,&cost);
            addedge(to, from, cost);
        }
        scanf("%d",&goodcnt);
        for(int i=0; i<goodcnt; i++)
            scanf("%d",&id[i]);
        int ans = 1e9;
        SPFA(key);
        for(int i=0; i<goodcnt; i++)
            ans = min(ans, dis[id[i]]);
        if(ans == 1e9)  ans = -1;
        printf("%d\n",ans);
    }
    return 0;
}