codevs-1027

http://codevs.cn/problem/1027/
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int N=25;
int n,f[N][N],size,b[N],into[N],br[N],ans[N];
string id[N],name[N],s;
bool used[N],add[N],bb[N];
int check()
{
     for(int i=1;i<=size;++i)
     if(name[i]==s)return i;
     return -1;
}
int ccheck()
{
    for(int i=1;i<=n;++i)
    if(s==id[i])return i;
}
void Init()
{
     memset(f,1,sizeof f);
     scanf("%d",&n);
     for(int i=1;i<=n;++i)cin>>id[i];
     char ch[0];
     int tmp;
     scanf("%s",ch);
     while(ch[0]!='Q')
     {
         if(ch[0]=='E')
         {
             cin>>s;
             tmp=check();
             if(tmp==-1)
             {
                 name[++size]=s;
                 into[size]=1;
             }
             else into[tmp]=1;
         }
         if(ch[0]=='L')
         {
             cin>>s;
             tmp=check();
             into[tmp]=0;
         }
         if(ch[0]=='M')
         {
             cin>>s;
             tmp=ccheck();
             for(int i=1;i<=n;++i)
                if(!into[i])f[i][tmp]=0;
         }
         scanf("%s",ch);
     }
}
bool find(int t)
{
    for(int i=1;i<=n;++i)
    {
        if(!used[i]&&f[t][i])
        {
            used[i]=1;
            if(!b[i]||find(b[i]))
            {
                b[i]=t;
                return true;
            }
        }
    }
    return false;
}

void work()
{
    for(int i=1;i<=n;++i)
    {
        memset(used,0,sizeof(used));
        find(i);
    }
    for(int i=1;i<=n;++i)
    {
        if(b[i]>0)
        {
            memset(used,0,sizeof(used));
            for(int j=1;j<=n;++j) br[j]=b[j];
            f[b[i]][i]=0;
            b[i]=0;
            if(!find(br[i])) 
            {
                ans[br[i]]=i;
            }
            for(int j=1;j<=n;++j)b[j]=br[j];
            f[b[i]][i]=1;
        }
    }
    int temp;
    for(int i=1;i<=n;++i)
    {
        s="";
        for(int j=1;j<=n;++j)
        {
            if(!bb[j]&&(s==""||name[j]<s))s=name[j],temp=j;
        }
        bb[temp]=1;
        cout<<s<<":";
        if(ans[temp])cout<<id[ans[temp]]<<endl;
        else cout<<"???"<<endl;
    }
}

int main()
{
    Init();
    work();
    return 0;
}