1 #include <cstdio>
 2 #include <cstring>
 3 #include <vector>
 4 #include <queue>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 const int maxn = 1050;
 9 const int INF = 0x7ffffff;
10 
11 struct Edge {
12     int from, to, dist;
13     Edge(int u, int v, int d) :from(u), to(v), dist(d) {}
14 };
15 
16 struct HeapNode {
17     int d, u;
18     HeapNode(int dv, int uv) :d(dv), u(uv){}
19     bool operator < (const HeapNode& rhs) const {
20         return d > rhs.d;
21     }
22 };
23 struct Dijkstra {
24     int n, m;
25     Dijkstra(){};
26     Dijkstra(int nv, int mv) :n(nv), m(mv){}
27     vector<Edge> edges;
28     vector<int> G[maxn];
29     bool done[maxn]; //是否已永久标号
30     int d[maxn]; //s到各个点的距离
31     //int p[maxn]; //最短路中的上一条弧
32     void init(int n) {
33         this->n = n;
34         for (int i = 0; i < n; i++) G[i].clear();
35         edges.clear();
36     }
37     void AddEdge(Edge e) {
38         edges.push_back(e);
39         m = edges.size();
40         G[e.from].push_back(m - 1);
41     }
42     void dijkstra(int s) {
43         priority_queue<HeapNode> Q;
44         for (int i = 0; i < n; i++) d[i] = INF;
45         d[s] = 0;
46         memset(done, 0, sizeof(done));
47         Q.push(HeapNode(0, s));
48         while (!Q.empty()) {
49             HeapNode x = Q.top(); Q.pop();
50             int u = x.u;
51             if (done[u]) continue;
52             done[u] = true;
53             for (int i = 0; i < G[u].size(); i++) {
54                 Edge& e = edges[G[u][i]];
55                 if (d[e.to] > d[u] + e.dist) {
56                     d[e.to] = d[u] + e.dist;
57                     //p[e.to] = G[u][i];
58                     Q.push(HeapNode(d[e.to],e.to));
59                 }
60             }
61         }
62     }
63 };
64 
65 int ad[maxn];
66 int wt[maxn];
67 int main()
68 {
69     int T,S,D,t, a, b, r,ans,temp;
70     Dijkstra d;
71     while (scanf("%d%d%d", &T, &S, &D) == 3)
72     {
73         ans = INF;
74         d.init(1005);
75         for(int i=0;i<T;i++)
76         {
77             scanf("%d%d%d",&a,&b,&t);
78             d.AddEdge(Edge(a-1,b-1,t));
79             d.AddEdge(Edge(b-1,a-1,t));
80         }
81         for(int i=0;i<S;i++) scanf("%d",&ad[i]);
82         for(int i=0;i<D;i++) scanf("%d",&wt[i]);
83         for(int i=0;i<S;i++)
84         {
85             d.dijkstra(ad[i]-1);
86             for(int j=0;j<D;j++)
87             {
88                 if(ans>d.d[wt[j]-1]) ans=d.d[wt[j]-1];
89             }
90         }
91         printf("%d\n",ans);
92     }
93 }