Kindergarten（网络流解法）

题意：http://acm.hdu.edu.cn/showproblem.php?pid=2458

问你二分图的最大团是多大。

#define IOS ios_base::sync_with_stdio(0); cin.tie(0);
#include <cstdio>//sprintf islower isupper
#include <cstdlib>//malloc  exit strcat itoa system("cls")
#include <iostream>//pair
#include <fstream>//freopen("C:\\Users\\13606\\Desktop\\Input.txt","r",stdin);
#include <bitset>
//#include <map>
//#include<unordered_map>
#include <vector>
#include <stack>
#include <set>
#include <string.h>//strstr substr
#include <string>
#include <time.h>// srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;
#include <cmath>
#include <deque>
#include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less
#include <vector>//emplace_back
//#include <math.h>
#include <cassert>
#include <iomanip>
//#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor
#include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)
using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation
//******************
int lowbit(int n);
int Del_bit_1(int n);
clock_t __STRAT,__END;
double __TOTALTIME;
void _MS(){__STRAT=clock();}
void _ME(){__END=clock();__TOTALTIME=(double)(__END-__STRAT)/CLOCKS_PER_SEC;cout<<"Time: "<<__TOTALTIME<<" s"<<endl;}
//***********************
#define rint register int
#define fo(a,b,c) for(rint a=b;a<=c;++a)
#define fr(a,b,c) for(rint a=b;a>=c;--a)
#define mem(a,b) memset(a,b,sizeof(a))
#define pr printf
#define sc scanf
#define ls rt<<1
#define rs rt<<1|1
typedef pair<int,int> PII;
typedef vector<int> VI;
typedef long long ll;
const double E=2.718281828;
const double PI=acos(-1.0);
const ll INF=(1LL<<60);
const int inf=(1<<30);
const double ESP=1e-9;
const int mod=(int)1e9+7;
const int N=(int)4e2+10;
const int M=40010;

class DINIC
{
public:
//    const int MAXN=10004,MAXWAY=100005;
    int n,way,max_flow,deep[N];
    int tot,head[N],cur[N];
    struct EDGE{
        int to,next;
        int dis;
    }edge[M];
    void Init(int n_)
    {
        tot=-1;//因为加反向边要^1,所以要从0开始;
        n=n_;
        max_flow=0;
        for(int i=0;i<=n_;++i)
            head[i]=-1;
    }
    void add(int from,int to,int V)
    {
        //正向
        ++tot;
        edge[tot].to=to;
        edge[tot].dis=V;
        edge[tot].next=head[from];
        head[from]=tot;
        //反向
        swap(from,to);
        ++tot;
        edge[tot].to=to;
        edge[tot].dis=0;
        edge[tot].next=head[from];
        head[from]=tot;
    }
    queue<int>q;
    bool bfs(int s,int t)
    {
        for(int i=1;i<=n;++i)
            deep[i]=inf;
        while(!q.empty())q.pop();
        for(int i=1;i<=n;++i)cur[i]=head[i];
        deep[s]=0;
        q.push(s);

        while(!q.empty())
        {
            int now=q.front();q.pop();
            for(int i=head[now];i!=-1;i=edge[i].next)
            {
                if(deep[edge[i].to]==inf&&edge[i].dis)
                {
                    deep[edge[i].to]=deep[now]+1;
                    q.push(edge[i].to);
                }
            }
        }
        return deep[t]<inf;
    }
    int dfs(int now,int t,int limit)
    {
        if(!limit||now==t)return limit;
        int flow=0,f;
        for(int i=cur[now];i!=-1;i=edge[i].next)
        {
            cur[now]=i;
            if(deep[edge[i].to]==deep[now]+1&&(f=dfs(edge[i].to,t,min(limit,edge[i].dis))))
            {
                flow+=f;
                limit-=f;
                edge[i].dis-=f;
                edge[i^1].dis+=f;
                if(!limit)break;
            }
        }
        return flow;
    }
    void Dinic(int s,int t)
    {
        while(bfs(s,t))
            max_flow+=dfs(s,t,inf);
    }
}G;

int mp[N][N];

int main()
{
    int boy,girl,m;
    int cnt=0;
    while(~sc("%d%d%d",&boy,&girl,&m),boy||girl||m)
    {
        mem(mp,1);
        G.Init(boy+girl+2);
        for(int i=1;i<=m;++i)
        {
            int u,v;
            sc("%d%d",&u,&v);
            mp[u][v]=0;
        }
        int S=boy+girl+1,T=boy+girl+2;
        for(int i=1;i<=boy;++i)
            G.add(S,i,1);
        for(int i=boy+1;i<=boy+girl;++i)
            G.add(i,T,1);
        for(int i=1;i<=boy;++i)
            for(int j=1;j<=girl;++j)
                if(mp[i][j])
                    G.add(i,j+boy,inf);
        G.Dinic(S,T);
        pr("Case %d: %d\n",++cnt,boy+girl-G.max_flow);
    }
    return 0;
}

/**************************************************************************************/

int lowbit(int n)
{
    return n&(-n);
}

int Del_bit_1(int n)
{
    return n&(n-1);
}