1205. By the Underground or by Foot?(ｓｐｆａ）

１２０５

简单题　有一些小细节　两个站可能不相连　但是可以走过去

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 #include<vector>
 #include<queue>
 #include<cmath>
 using namespace std;
 #define INF 0xfffffff
 vector<int>ed[];
 double v1,v2,x[],y[],w[][],dis[];
 int n,vis[],pa[],o[];
 void spfa(int s,int e)
 {
     int i;
     for(i = ; i <= n ; i++)
     dis[i] = INF;
     dis[s] = ;
     queue<int>q;
     vis[s] = ;
     q.push(s);
     while(!q.empty())
     {
         int u  = q.front();
         q.pop();
         vis[u] = ;
         for(i =  ; i < (int)ed[u].size() ; i++)
         {
             int v = ed[u][i];
             if(dis[v]>dis[u]+w[u][v])
             {
                 pa[v] = u;
                 dis[v] = dis[u]+w[u][v];
                 if(!vis[v])
                 {
                     vis[v] = ;
                     q.push(v);
                 }
             }
         }
     }
     printf("%.7lf\n",dis[e]);
     int g = ,x=e;
     while(pa[x]!=s)
     {
         x = pa[x];
         g++;
         o[g] = x;
     }
     printf("%d",g);
     for(i = g ; i>= ; i--)
     printf(" %d",o[i]);
     puts("");
 }
 double dist(int u,int v)
 {
     double s = sqrt((x[u]-x[v])*(x[u]-x[v])+(y[u]-y[v])*(y[u]-y[v]));
     return s;
 }
 int main()
 {
     int i,j,u,v;
     cin>>v1>>v2;
     cin>>n;
     for(i = ; i <= n ;i++)
     {
         scanf("%lf%lf",&x[i],&y[i]);
     }
     for(i =  ;i <= n+ ; i++)
         for(j =   ; j <= n+ ; j++)
         w[i][j] = INF;
     while(scanf("%d%d",&u,&v)!=EOF)
     {
         if(!u&&!v)
         break;
         w[u][v] = dist(u,v)/v2;
         w[v][u] = w[u][v];
         ed[u].push_back(v);
         ed[v].push_back(u);
     }
     for(i = ; i <= n ; i++)
         for(j = i+ ;j <= n ;j++)
         {
             if(w[i][j]==INF)
             {
                 w[i][j] = dist(i,j)/v1;
                 w[j][i] = w[i][j]/v1;
                 ed[i].push_back(j);
                 ed[j].push_back(i);
             }
         }
     scanf("%lf%lf%lf%lf",&x[],&y[],&x[n+],&y[n+]);
     for(i = ; i <= n+ ;i++)
     {
         w[][i] = dist(i,)/v1;
         w[i][] = w[][i];
         ed[].push_back(i);
         ed[i].push_back();
         w[n+][i] = dist(i,n+)/v1;
         w[i][n+] = w[n+][i];
         ed[i].push_back(n+);
         ed[n+].push_back(i);
     }
     n++;
     for(i = ; i <= n ;i++)
     w[i][i] = ;
     spfa(,n);
     return ;
 }