HDU 2066 一个人的旅行

题解：最短路~

#include <cstdio>

#include <utility>

#include <cstring>

#include <queue>

using namespace std;

const int N=20005;

const int INF=9999999;

typedef pair<int,int>seg;

priority_queue<seg,vector<seg>,greater<seg> >q;

int d[N],u[N],v[N],w[N],head[N],next[N],a,b,c,m,n,k,p,cnt,min;

bool vis[N];

void build(){

    memset(head,-1,sizeof(head));

    for(int e=1;e<=m;e++){

        scanf("%d%d%d",&u[e],&v[e],&w[e]);

        n=n<u[e]?u[e]:n;

        n=n<v[e]?v[e]:n;

        u[e+m]=v[e]; v[e+m]=u[e]; w[e+m]=w[e];

        next[e]=head[u[e]]; head[u[e]]=e;

        next[e+m]=head[u[e+m]]; head[u[e+m]]=e+m;

    }

}

int Dijkstra(int src){

    memset(vis,0,sizeof(vis));

    for(int i=0;i<=n;i++)d[i]=INF;

    d[src]=0;

    q.push(make_pair(d[src],src));

    while(!q.empty()){

        seg now=q.top(); q.pop();

        int x=now.second;

        if (vis[x]) continue; vis[x]=1;

        for(int e=head[x];e!=-1;e=next[e])

        if(d[v[e]]>d[x]+w[e]){

            d[v[e]]=d[x]+w[e];

            q.push(make_pair(d[v[e]],v[e]));

        }

        

    }

}

int main(){

    while(~scanf("%d%d%d",&m,&k,&p)){

        build();

        for(int e=2*m+1;e<=2*m+k;e++){

            scanf("%d",&v[e]);

            w[e]=0; u[e]=2*m+k+1;

            next[e]=head[u[e]]; head[u[e]]=e;

        }

        Dijkstra(2*m+k+1);

        int min=INF;

        for(int i=0;i<p;i++){

            scanf("%d",&a);

            min=d[a]<min?d[a]:min;

        }      

        printf("%d\n",min);             

    }

    return 0;

}