1 #include<cstdio> 2 #include<cstring> 3 #include<algorithm> 4 #include<queue> 5 using namespace std; 6 #define INF 2147483647 7 #define MAXN 201 8 #define MAXM 1501 9 int v[MAXM],cap[MAXM],en,first[MAXN],next[MAXM];10 int d[MAXN],cur[MAXN];11 queue<int>q;12 int m,S,T,W;13 char U[1],V[1];14 void Init_Dinic(){memset(first,-1,sizeof(first)); en=0; S=‘A‘; T=‘Z‘;}15 void AddEdge(const int &U,const int &V,const int &W)16 {v[en]=V; cap[en]=W; next[en]=first[U]; first[U]=en++;17 v[en]=U; next[en]=first[V]; first[V]=en++;}18 bool bfs()19 {20     memset(d,-1,sizeof(d)); q.push(S); d[S]=0;21     while(!q.empty())22       {23         int U=q.front(); q.pop();24         for(int i=first[U];i!=-1;i=next[i])25           if(d[v[i]]==-1 && cap[i])26             {27               d[v[i]]=d[U]+1;28               q.push(v[i]);29             }30       }31     return d[T]!=-1;32 }33 int dfs(int U,int a)34 {35     if(U==T || !a) return a;36     int Flow=0,f;37     for(int &i=cur[U];i!=-1;i=next[i])38       if(d[U]+1==d[v[i]] && (f=dfs(v[i],min(a,cap[i]))))39         {40           cap[i]-=f; cap[i^1]+=f;41           Flow+=f; a-=f; if(!a) break;42         }43     if(!Flow) d[U]=-1;44     return Flow;45 }46 int max_flow()47 {48     int Flow=0,tmp=0;49     while(bfs())50       {51         memcpy(cur,first,sizeof(cur));52         while(tmp=dfs(S,INF)) Flow+=tmp;53       }54     return Flow;55 }56 int main()57 {58     scanf("%d",&m); Init_Dinic();59     for(int i=1;i<=m;++i)60       {61           scanf("%s%s%d",U,V,&W);62           AddEdge(U[0],V[0],W);63       }64     printf("%d\n",max_flow());65     return 0;66 }