1552G - A Serious Referee - CodeForces Solution

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int n,k,d[14];
ll MSK,msk[14],s[14][44],all;
vector<int>vec;
void dfs(int p,ll m){
	if(p==k){
		int tmp=__builtin_popcountll(m);
		if((1ll<<tmp)-1!=m)puts("REJECTED"),exit(0);
		return;
	}
	int v=__builtin_popcountll(m&msk[p]);m^=(m&msk[p]);
	for(int i=0;i<=d[p];i++)vec.push_back(i),dfs(p+1,m|s[p][v+i]),vec.pop_back();
}
int main(){
	scanf("%d%d",&n,&k);
	if(n==1)return puts("ACCEPTED"),0;
	for(int i=0;i<k;i++){
		int m;scanf("%d",&m);
		for(int j=0,x;j<m;j++){
			scanf("%d",&x),x--;
			msk[i]|=1ll<<x,s[i][j+1]=msk[i];
		}
		d[i]=__builtin_popcountll(msk[i]^(MSK&msk[i])),MSK|=msk[i];
	}
	if(MSK!=(1ll<<n)-1)return puts("REJECTED"),0;
	dfs(0,0),puts("ACCEPTED");
}