POJ 2394 Dijkstra

题意：







思路：

裸的Dijkstra 爆敲一发模板

//By SiriusRen
#include <queue>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define N 2222
int f,p,c,m,xx,yy,zz,w[N],v[N],next[N],first[N],tot,dis[N],vis[N],ans,s[N];
struct Node{int now,weight;}jy;
priority_queue<Node>pq;
void add(int x,int y,int z){
    w[tot]=z,v[tot]=y,next[tot]=first[x],first[x]=tot++;
}
bool operator < (Node a,Node b){
    return a.weight>b.weight;
}
void Dijkstra(){
    memset(dis,0x3f,sizeof(dis));
    dis[1]=0;
    jy.now=1,jy.weight=0;
    pq.push(jy);
    while(!pq.empty()){
        Node t=pq.top();pq.pop();
        if(vis[t.now])continue;
        vis[t.now]=1;
        for(int i=first[t.now];~i;i=next[i])
            if(!vis[v[i]]&&dis[v[i]]>dis[t.now]+w[i]){
                dis[v[i]]=dis[t.now]+w[i];
                jy.now=v[i],jy.weight=dis[v[i]];
                pq.push(jy);
            }
    }
}
int main(){
    memset(first,-1,sizeof(first));
    scanf("%d%d%d%d",&f,&p,&c,&m);
    for(int i=1;i<=p;i++){
        scanf("%d%d%d",&xx,&yy,&zz);
        add(xx,yy,zz),add(yy,xx,zz);
    }
    Dijkstra();
    for(int i=1;i<=c;i++){
        scanf("%d",&xx);
        if(dis[xx]<=m)
            s[++ans]=i;
    }
    printf("%d\n",ans);
    for(int i=1;i<=ans;i++)
        printf("%d\n",s[i]);
}