<span>HDU3829 Cat VS Dog（最大独立集）</span>

/* ***********************************************
Author        :devil
Created Time  :2016/5/17 17:13:21
************************************************ */
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <cmath>
#include <stdlib.h>
using namespace std;
const int N=510;
int link[N],c,d,n;
string s1[N],s2[N];
bool vis[N];
vector<int>eg[N];
bool dfs(int u)
{
    for(int i=0;i<eg[u].size();i++)
    {
        int v=eg[u][i];
        if(!vis[v])
        {
            vis[v]=1;
            if(link[v]==-1||dfs(link[v]))
            {
                link[v]=u;
                return 1;
            }
        }
    }
    return 0;
}
int main()
{
    //freopen("in.txt","r",stdin);
    while(~scanf("%d%d%d",&c,&d,&n))
    {
        memset(link,-1,sizeof(link));
        for(int i=1;i<=n;i++)
            eg[i].clear();
        for(int i=1;i<=n;i++)
            cin>>s1[i]>>s2[i];
        for(int i=1;i<n;i++)
        {
            for(int j=i+1;j<=n;j++)
            {
                if(s1[i]==s2[j]||s1[j]==s2[i])
                {
                    eg[i].push_back(j);
                    eg[j].push_back(i);
                }
            }
        }
        int ans=0;
        for(int i=1;i<=n;i++)
        {
            memset(vis,0,sizeof(vis));
            ans+=dfs(i);
        }
        printf("%d\n",n-ans/2);
    }
    return 0;
}