• Source 
    1. #include <iostream>
    2. #include <vector>
    3. #include <queue> 
    4. using namespace std;
    5. const int N=109;
    6. vector<int> graph[N];
    7. bool mark[N];
    8. queue< pair<int,int> > q;
    9. int main()
    10. {
    11. 	int n;
    12. 	cin>>n;
    13. 	vector<int> ans[3];
    14. 	for(int i=1;i<=n;++i)
    15. 	{
    16. 		int b;
    17. 		cin>>b;
    18. 		while(b!=0)
    19. 		{
    20. 			graph[i].push_back(b);
    21. 			cin>>b;
    22. 		}
    23. 	}
    24. 	for(int i=1;i<=n;++i)
    25. 	{
    26. 		if(mark[i]==false)
    27. 		{
    28. 			q.push(make_pair(i,1));
    29. 			ans[1].push_back(i);
    30. 			mark[i]=true;
    31. 			while(!q.empty())
    32. 			{
    33. 				pair<int,int> p=q.front();
    34. 				q.pop();
    35. 				int t;
    36. 				if(p.second==1)
    37. 					t=2;
    38. 				else
    39. 					t=1;
    40. 				for(int i=0;i<graph[p.first].size();++i)
    41. 					if(mark[graph[p.first][i]]==false)
    42. 					{
    43. 						mark[graph[p.first][i]]=true;
    44. 						q.push(make_pair(graph[p.first][i],t));
    45. 						ans[t].push_back(graph[p.first][i]);
    46. 					}
    47. 			}
    48. 		}
    49. 	}
    50. 	bool team1[N],team2[N];
    51. 	for(int i=0;i<ans[1].size();++i)
    52. 		team1[ans[1][i]]=true;
    53. 	for(int i=0;i<ans[2].size();++i)
    54. 		team2[ans[2][i]]=true;
    55. 	bool check=true;
    56. 	for(int i=0;i<ans[1].size();++i)
    57. 	{
    58. 		check=false;
    59. 		for(int j=0;j<graph[ans[1][i]].size();++j)
    60. 			if(team2[graph[ans[1][i]][j]]==true)
    61. 				check=true;
    62. 		if(!check)
    63. 			break;
    64. 	}
    65. 	if(!check)
    66. 		cout<<0;
    67. 	else
    68. 	{
    69. 		cout<<ans[1].size()<<endl;
    70. 		for(int i=0;i<ans[1].size();++i)
    71. 			cout<<ans[1][i]<<" ";
    72. 	}
    73. 	return 0;
    74.  
    75. }