HDU 2122 HDU Today【Floyd】

 1 #include<iostream>  
 2 #include<cstdio>  
 3 #include<cstring> 
 4 #include <cmath> 
 5 #include<stack>
 6 #include<vector>
 7 #include<map> 
 8 #include<set>
 9 #include<queue> 
10 #include<algorithm>  
11 #define mod=1e9+7;
12 using namespace std;
13 
14 typedef long long LL;
15 const int INF = 10000000;
16 const int maxn=1005;
17 map<string,int> mp;
18 int d[maxn][maxn];
19 

20 int main(){
21     int n,i,j,k,w;
22     string st,en,s1,s2;
23     while(scanf("%d",&n)!=EOF&&(n!=-1)){
24         mp.clear();
25         int cnt=0;
26         
27         for(i=0;i<maxn;i++){
28             for(j=0;j<maxn;j++){
29                 if(i==j) d[i][j]=0;
30                 else d[i][j]=INF;
31             }
32         }
33         
34         cin>>st>>en;
35         if(!mp[st]) mp[st]=cnt++;
36         if(!mp[en]) mp[en]=cnt++;
37         
38         for(i=0;i<n;i++){
39             cin>>s1>>s2>>w;
40             if(!mp[s1]) mp[s1]=cnt++;
41             if(!mp[s2]) mp[s2]=cnt++;
42             
43             if(d[mp[s1]][mp[s2]]>w) d[mp[s1]][mp[s2]]=d[mp[s2]][mp[s1]]=w;            
44         }
45         
46         for(k=0;k<cnt;k++)
47          for(i=0;i<cnt;i++)
48           for(j=0;j<cnt;j++)
49            d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
50            
51            if(d[mp[st]][mp[en]]==INF) printf("-1\n");
52            else printf("%d\n",d[mp[st]][mp[en]]);                
53     }
54     return 0;
55 }