【bitset】Kth Minimum Clique

#include<bits/stdc++.h>
#define B bitset<105>
using namespace std;
typedef long long ll ;
const int N = 105 ;
B G[N] ;
ll a[N] ;
typedef struct Node {
    B mask;
    ll val;
    Node() {}
    Node( B b,ll v):mask(b),val(v){}
    bool operator < (const Node & rhs )const {
        return val > rhs.val ;
    }
}Node ;
int main()
{
    int n,k;
    while(~scanf("%d%d",&n,&k)){
        for(int i=1;i<=n;i++){
            scanf("%lld",&a[i]);
        }
        for(int i=1;i<=n;i++){
            G[i].reset();
            for(int j=1,x;j<=n;j++){
                scanf("%1d",&x);
                G[i][j] = x ;
            }
        }
        priority_queue < Node > Q ;
        B tmp ;
        tmp.reset();
        Q.push( Node(tmp,0) );
        while( !Q.empty() ){
            Node cur = Q.top() ;
            Q.pop();
            if( !(--k) ){
                return 0*printf("%lld
",cur.val );
            }
            int pos = 1 ;
            for(int i=1;i<=n;i++){
                if(cur.mask[i]){
                    pos = i+1 ;
                }
            }
            for(int i=pos;i<=n;i++){
                if( ( G[i] & cur.mask ) == cur.mask ){
                    cur.mask[i] = 1 ;
                    Q.push( Node(cur.mask,cur.val +a[i]) );
                    cur.mask[i] = 0 ;
                }
            }
        }
        puts("-1");
    }
    return 0;
}