UVA 11825(Hacker's Crackdown-集合)

给一个集合U和一堆子集
最多把子集分成多少份,使每份的并为全集U?

集合子集的遍历 for(int S0 = S; S0; S0 = (S0-1)&S)

#include<bits/stdc++.h>
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define Rep(i,n) for(int i=0;i<n;i++)
#define ForD(i,n) for(int i=n;i;i--)
#define ForkD(i,k,n) for(int i=n;i>=k;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=Pre[x];p;p=Next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=Next[p]) 
#define Lson (o<<1)
#define Rson ((o<<1)+1)
#define MEM(a) memset(a,0,sizeof(a));
#define MEMI(a) memset(a,127,sizeof(a));
#define MEMi(a) memset(a,128,sizeof(a));
#define INF (2139062143)
#define F (100000007)
#define pb push_back
#define mp make_pair 
#define fi first
#define se second
#define vi vector<int> 
#define pi pair<int,int>
#define SI(a) ((a).size())
typedef long long ll;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return (a-b+llabs(a-b)/F*F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
int read()
{
    int x=0,f=1; char ch=getchar();
    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
    return x*f;
} 
#define MAXN (17)
int f[1<<17],P[1<<17],cover[1<<17];
int main()
{
// freopen("uva11825.in","r",stdin);
// freopen(".out","w",stdout);


    int n,kcase=1;
    while (n=read()) {
        int ALL=(1<<n)-1;
        Rep(i,n) {
            P[i]=1<<i;
            int m=read();
            while (m--) P[i]|=1<<( read() );
        }   
        Rep(S,1<<n) {
            cover[S] = 0;
            Rep(i,n) if (S & (1<<i) ) cover[S]|=P[i];
        } 
        Rep(S,1<<n) {
            f[S]=0;
            for(int S0 = S; S0; S0 = (S0-1)&S)
                if (cover[S0]==ALL) 
                    f[S] = max( f[S], f[S-S0] + 1);
        }

        printf("Case %d: %d\n",kcase++,f[ALL]);
    }


    return 0;
}