hdu 2112 map+Dijkstra

无向图 用map 起点和终点可能一样 数组不能开太大 WA了好多发

Sample Input
6
xiasha westlake //起点 终点
xiasha station 60
xiasha ShoppingCenterofHangZhou 30
station westlake 20
ShoppingCenterofHangZhou supermarket 10
xiasha supermarket 50
supermarket westlake 10
-1

Sample Output
50

 # include <iostream>
 # include <cstdio>
 # include <cstring>
 # include <string>
 # include <algorithm>
 # include <cmath>
 # include <queue>
 # include <map>
 # define LL long long
 using namespace std ;

 const int INF=0x3f3f3f3f;
 const int MAXN=;

 int n ;
 map<string,int> mp ;
 bool vis[MAXN];
 int cost[MAXN][MAXN] ;
 int lowcost[MAXN] ;

 void Dijkstra(int beg)
 {
     for(int i=;i<n;i++)
     {
         lowcost[i]=INF;vis[i]=false;
     }
     lowcost[beg]=;
     for(int j=;j<n;j++)
     {
         int k=-;
         int Min=INF;
         for(int i=;i<n;i++)
             if(!vis[i]&&lowcost[i]<Min)
             {
                 Min=lowcost[i];
                 k=i;
             }
             if(k==-)
                 break ;
             vis[k]=true;
             for(int i=;i<n;i++)
                 if(!vis[i]&&lowcost[k]+cost[k][i]<lowcost[i])
                 {
                     lowcost[i]=lowcost[k]+cost[k][i];

                 }
     }

 }

 int main ()
 {
    // freopen("in.txt","r",stdin) ;
    int m ;
    while(cin>>m)
    {
        if (m == -)
         break ;
        mp.clear() ;
        string s1 ,s2 ;
        int i , j , w ;
        for (i =  ; i < MAXN ; i++)
         for (j =  ; j < MAXN ; j++)
        {
            if (i == j)
               cost[i][j] =  ;
            else
               cost[i][j] = INF ;
        }

        cin>>s1>>s2 ;
        mp[s1] =  ;
        mp[s2] =  ;
        n =  ;
        bool flag =  ;
        if (s1 == s2)
           flag =  ;
        while(m--)
        {
            cin>>s1>>s2>>w ;
            if (!mp[s1])
                mp[s1] = n++ ;
            if (!mp[s2])
                mp[s2] = n++ ;
            if (w < cost[mp[s1]-][mp[s2]-])
            {
                cost[mp[s1]-][mp[s2]-] = w ;
                cost[mp[s2]-][mp[s1]-] = w ;
            }

        }
        n-- ;
        if (flag)
        {
            cout<<<<endl ;
            continue ;
        }
        Dijkstra() ;

        if (lowcost[] != INF)
           cout<<lowcost[]<<endl ;
        else
           cout<<-<<endl ;

    }

     return  ;
 }