【uva 753】A Plug for UNIX（图论--最大流 Dinic）

  1 #include<cstdio>
  2 #include<cstdlib>
  3 #include<cstring>
  4 #include<algorithm>
  5 #include<iostream>
  6 #include<queue>
  7 using namespace std;
  8 
  9 const int N=110,M=110,K=110;
 10 const int NN=310,MM=310,INF=(int)1e9;
 11 int n,m,k,ts,st,ed,len;
 12 int d[NN],last[NN];
 13 char s[N],ss[N],str[3*N][N];//,sb[M][N];
 14 struct edge{int x,y,fl,next;}a[MM];
 15 queue<int> q;
 16 
 17 int mmin(int x,int y) {return x<y?x:y;}
 18 int get_id()
 19 {
 20     for (int i=1;i<=ts;i++)
 21       if (!strcmp(s,str[i])) return i;
 22     strcpy(str[++ts],s);
 23     return ts;
 24 }
 25 void ins(int x,int y,int fl)
 26 {
 27     a[++len].x=x,a[len].y=y,a[len].fl=fl;
 28     a[len].next=last[x],last[x]=len;
 29     a[++len].x=y,a[len].y=x,a[len].fl=0;
 30     a[len].next=last[y],last[y]=len;
 31 }
 32 bool bfs()
 33 {
 34     memset(d,-1,sizeof(d));
 35     while(!q.empty()) q.pop();//这里死循环？？？-_-|||
 36     q.push(st); d[st]=1;
 37     while (!q.empty())
 38     {
 39       int x=q.front(); q.pop();
 40       for (int i=last[x];i;i=a[i].next)
 41       {
 42         int y=a[i].y;
 43         if (d[y]!=-1||!a[i].fl) continue;//fl
 44         d[y]=d[x]+1, q.push(y);
 45         //if (y==ed) break;//不这样为了第61行的优化
 46       }
 47     }
 48     if (d[ed]==-1) return false;
 49     return true;
 50 }
 51 int dfs(int x,int flow)
 52 {
 53     if (x==ed) return flow;
 54     int sum=0;
 55     for (int i=last[x];i;i=a[i].next)
 56     {
 57       int y=a[i].y;
 58       if (d[y]!=d[x]+1||!a[i].fl) continue;//
 59       int t=dfs(y, mmin(a[i].fl,flow-sum));
 60       a[i].fl-=t, a[i^1].fl+=t;
 61       sum+=t;
 62       if (sum==flow) break;
 63     }
 64     if (sum==0) d[x]=-1;//
 65     return sum;
 66 }
 67 int Dinic()
 68 {
 69     int sum=0;
 70     while (bfs())
 71       sum+=dfs(st,INF);//到这个点时的容量为INF
 72     return sum;
 73 }
 74 int main()
 75 {
 76     int T,x,y;
 77     scanf("%d",&T);
 78     while (T--)
 79     {
 80       st=1,ed=2,len=1,ts=2;
 81       scanf("%d",&n);
 82       memset(last,0,sizeof(last));
 83       for (int i=1;i<=n;i++)
 84       {
 85         scanf("%s",s);
 86         x=get_id();
 87         ins(x,ed,1);
 88       }
 89       scanf("%d",&m);
 90       for (int i=1;i<=m;i++)
 91       {
 92         scanf("%s%s",s,s);
 93         x=get_id();
 94         ins(st,x,1);
 95       }
 96       scanf("%d",&k);
 97       for (int i=1;i<=k;i++)
 98       {
 99         scanf("%s",s);
100         x=get_id();
101         scanf("%s",s);
102         y=get_id();
103         ins(x,y,1);
104       }
105       int ans=Dinic();
106       if (T) printf("\n");
107       printf("%d\n",m-ans);
108     }
109     return 0;
110 }