题意：http://acm.hdu.edu.cn/showproblem.php?pid=2458
问你二分图的最大团是多大。
1 #define IOS ios_base::sync_with_stdio(0); cin.tie(0);
2 #include <cstdio>//sprintf islower isupper
3 #include <cstdlib>//malloc exit strcat itoa system("cls")
4 #include <iostream>//pair
5 #include <fstream>//freopen("C:\\Users\\13606\\Desktop\\Input.txt","r",stdin);
6 #include <bitset>
7 //#include <map>
8 //#include<unordered_map>
9 #include <vector>
10 #include <stack>
11 #include <set>
12 #include <string.h>//strstr substr
13 #include <string>
14 #include <time.h>// srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;
15 #include <cmath>
16 #include <deque>
17 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less
18 #include <vector>//emplace_back
19 //#include <math.h>
20 #include <cassert>
21 #include <iomanip>
22 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor
23 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)
24 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation
25 //******************
26 int lowbit(int n);
27 int Del_bit_1(int n);
28 clock_t __STRAT,__END;
29 double __TOTALTIME;
30 void _MS(){__STRAT=clock();}
31 void _ME(){__END=clock();__TOTALTIME=(double)(__END-__STRAT)/CLOCKS_PER_SEC;cout<<"Time: "<<__TOTALTIME<<" s"<<endl;}
32 //***********************
33 #define rint register int
34 #define fo(a,b,c) for(rint a=b;a<=c;++a)
35 #define fr(a,b,c) for(rint a=b;a>=c;--a)
36 #define mem(a,b) memset(a,b,sizeof(a))
37 #define pr printf
38 #define sc scanf
39 #define ls rt<<1
40 #define rs rt<<1|1
41 typedef pair<int,int> PII;
42 typedef vector<int> VI;
43 typedef long long ll;
44 const double E=2.718281828;
45 const double PI=acos(-1.0);
46 const ll INF=(1LL<<60);
47 const int inf=(1<<30);
48 const double ESP=1e-9;
49 const int mod=(int)1e9+7;
50 const int N=(int)4e2+10;
51 const int M=40010;
52
53 class DINIC
54 {
55 public:
56 // const int MAXN=10004,MAXWAY=100005;
57 int n,way,max_flow,deep[N];
58 int tot,head[N],cur[N];
59 struct EDGE{
60 int to,next;
61 int dis;
62 }edge[M];
63 void Init(int n_)
64 {
65 tot=-1;//因为加反向边要^1,所以要从0开始;
66 n=n_;
67 max_flow=0;
68 for(int i=0;i<=n_;++i)
69 head[i]=-1;
70 }
71 void add(int from,int to,int V)
72 {
73 //正向
74 ++tot;
75 edge[tot].to=to;
76 edge[tot].dis=V;
77 edge[tot].next=head[from];
78 head[from]=tot;
79 //反向
80 swap(from,to);
81 ++tot;
82 edge[tot].to=to;
83 edge[tot].dis=0;
84 edge[tot].next=head[from];
85 head[from]=tot;
86 }
87 queue<int>q;
88 bool bfs(int s,int t)
89 {
90 for(int i=1;i<=n;++i)
91 deep[i]=inf;
92 while(!q.empty())q.pop();
93 for(int i=1;i<=n;++i)cur[i]=head[i];
94 deep[s]=0;
95 q.push(s);
96
97 while(!q.empty())
98 {
99 int now=q.front();q.pop();
100 for(int i=head[now];i!=-1;i=edge[i].next)
101 {
102 if(deep[edge[i].to]==inf&&edge[i].dis)
103 {
104 deep[edge[i].to]=deep[now]+1;
105 q.push(edge[i].to);
106 }
107 }
108 }
109 return deep[t]<inf;
110 }
111 int dfs(int now,int t,int limit)
112 {
113 if(!limit||now==t)return limit;
114 int flow=0,f;
115 for(int i=cur[now];i!=-1;i=edge[i].next)
116 {
117 cur[now]=i;
118 if(deep[edge[i].to]==deep[now]+1&&(f=dfs(edge[i].to,t,min(limit,edge[i].dis))))
119 {
120 flow+=f;
121 limit-=f;
122 edge[i].dis-=f;
123 edge[i^1].dis+=f;
124 if(!limit)break;
125 }
126 }
127 return flow;
128 }
129 void Dinic(int s,int t)
130 {
131 while(bfs(s,t))
132 max_flow+=dfs(s,t,inf);
133 }
134 }G;
135
136 int mp[N][N];
137
138 int main()
139 {
140 int boy,girl,m;
141 int cnt=0;
142 while(~sc("%d%d%d",&boy,&girl,&m),boy||girl||m)
143 {
144 mem(mp,1);
145 G.Init(boy+girl+2);
146 for(int i=1;i<=m;++i)
147 {
148 int u,v;
149 sc("%d%d",&u,&v);
150 mp[u][v]=0;
151 }
152 int S=boy+girl+1,T=boy+girl+2;
153 for(int i=1;i<=boy;++i)
154 G.add(S,i,1);
155 for(int i=boy+1;i<=boy+girl;++i)
156 G.add(i,T,1);
157 for(int i=1;i<=boy;++i)
158 for(int j=1;j<=girl;++j)
159 if(mp[i][j])
160 G.add(i,j+boy,inf);
161 G.Dinic(S,T);
162 pr("Case %d: %d\n",++cnt,boy+girl-G.max_flow);
163 }
164 return 0;
165 }
166
167 /**************************************************************************************/
168
169 int lowbit(int n)
170 {
171 return n&(-n);
172 }
173
174 int Del_bit_1(int n)
175 {
176 return n&(n-1);
177 }