HDU ACM 3006 The Number of set (位运算)

 http://acm.hdu.edu.cn/showproblem.php?pid=3006

 

 

#include <iostream>
using namespace std;
const int MAX = 0x0007fff;
int used[MAX] = {0};
int main(){
    int n,m;
    while(cin>>n>>m){
        m = 1<<m;
        memset(used,0,sizeof(used));
        int i;
        for(i=0;i<n;i++){
            int k;
            cin>>k;
            int j;
            int ans = 0;
            for(j=0;j<k;j++){
                int x;
                cin>>x;
                ans = ans | 1<<(x-1);
            }
            used[ans] = 1;
            for(j=0;j<m;j++){
                if(used[j] == 1){
                    used[j | ans] = 1;
                }
            }
        }
        
        int num = 0;
        for(i=0;i<m;i++){
            if(used[i] == 1){
                num++;
            }
        }
        cout<<num<<endl;
    }
    return 0;
}