hdu2066多源最短路

题目链接：http://icpc.njust.edu.cn/Problem/Hdu/2066/

SPFA可以高效过，代码如下：

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef unsigned int ui;
 4 typedef long long ll;
 5 typedef unsigned long long ull;
 6 #define pf printf
 7 #define mem(a,b) memset(a,b,sizeof(a))
 8 #define prime1 1e9+7
 9 #define prime2 1e9+9
10 #define pi 3.14159265
11 #define lson l,mid,rt<<1
12 #define rson mid+1,r,rt<<1|1
13 #define scand(x) scanf("%llf",&x) 
14 #define f(i,a,b) for(int i=a;i<=b;i++)
15 #define scan(a) scanf("%d",&a)
16 #define mp(a,b) make_pair((a),(b))
17 #define P pair<int,int>
18 #define dbg(args) cout<<#args<<":"<<args<<endl;
19 #define inf 0x3f3f3f3f
20 const int maxn=1e4;
21 int n,m,t,e;
22 int head[maxn],in[maxn],nxt[maxn],d[maxn],a[maxn],ans,b;
23 bool vis[maxn];
24 struct edge{
25     int v,w;
26 }p[maxn];
27 void init()
28 {
29     e=0;
30     mem(head,-1);
31     mem(nxt,-1);
32     mem(vis,0);
33 }
34 void addedge(int u,int v,int w)
35 {
36     p[e].v=v;
37     p[e].w=w;
38     nxt[e]=head[u];
39     head[u]=e++;
40 }
41 void SPFA(int src)
42 {
43         mem(in,0);
44         d[src]=0;
45         queue<int>q;
46         q.push(src);
47         in[src]=1;
48         while(!q.empty())
49         {
50             int now=q.front();
51             q.pop();
52             in[now]=0;
53             for(int i=head[now];~i;i=nxt[i])
54             {
55                 if(d[p[i].v]>d[now]+p[i].w)
56                 {
57                     d[p[i].v]=d[now]+p[i].w;
58                     if(vis[p[i].v])ans=min(ans,d[p[i].v]);
59                     if(!in[p[i].v])
60                     {
61                         in[p[i].v]=1;
62                         q.push(p[i].v);
63                     }
64                 }
65             }
66         }
67 }
68 int main()
69 {
70     //freopen("input.txt","r",stdin);
71     //freopen("output.txt","w",stdout);
72     std::ios::sync_with_stdio(false);
73     while(scanf("%d%d%d",&n,&m,&t)!=EOF)
74     {
75         init();
76          ans=inf;
77         int u,v,w;
78         f(i,1,n)
79         {
80             scanf("%d%d%d",&u,&v,&w);
81             addedge(u,v,w);
82             addedge(v,u,w);
83         }
84         f(i,1,m)scan(a[i]);
85         f(i,1,t)
86         {
87             scan(b);
88             vis[b]=1;
89         }
90         f(i,1,m)
91         {
92             SPFA(a[i]);
93         }
94         pf("%d\n",ans);
95     }
96  }