HDU 2112 Today(Djikstra+map)

 1 #include<iostream>
 2 #include<string>
 3 #include<map>
 4 const int N=155;
 5 const int INF=1<<30-1;
 6 using namespace std;
 7 
 8 int V,E;
 9 int cost[N][N];
10 int dis[N];
11 bool used[N];
12 
13 void dij(int s){
14     for(int i=1;i<=V;i++){
15         dis[i]=INF;
16         used[i]=false;
17     }
18     dis[s]=0;
19     
20     while(true){
21         int k=-1;
22         for(int i=1;i<=V;i++){
23             if(!used[i]&&(k==-1||dis[k]>dis[i]))
24                 k=i;
25         }
26         if(k==-1) break;
27         used[k]=true;
28         for(int i=1;i<=V;i++){
29             if(dis[i]>dis[k]+cost[k][i])
30                 dis[i]=dis[k]+cost[k][i];
31         }
32     }
33 }
34 
35 int main(){
36     
37     while(cin>>E&&E!=-1){
38         map<string,int>mp;
39         string start,end;
40         int num=0;
41         cin>>start>>end;
42         //提前给起点终点赋好值 
43         mp[start]=++num;
44         mp[end]=++num;
45         for(int i=1;i<N;i++){
46             for(int j=1;j<N;j++){
47                 cost[i][j]=(i==j?0:INF);
48             }
49         }    
50         for(int i=1;i<=E;i++){
51             string s1,s2;
52             int val;
53             cin>>s1>>s2>>val;    
54             if(mp.find(s1)==mp.end()){
55                 mp[s1]=++num;
56             }
57             if(mp.find(s2)==mp.end()){
58                 mp[s2]=++num;
59             }
60             cost[mp[s1]][mp[s2]]=val;
61             cost[mp[s2]][mp[s1]]=val;
62         }
63         V=num;
64         dij(mp[start]);
65         //特判 
66         if(start==end){
67             cout<<"0"<<endl;
68             continue;
69         }
70         if(dis[mp[end]]!=INF)
71             cout<<dis[mp[end]]<<endl;
72         else
73             cout<<"-1"<<endl;
74     }
75 }