View Compilation Error

0_0_18227462_9320.cpp: In function 'void bfs(int)':
0_0_18227462_9320.cpp:37:5: error: 'vec' was not declared in this scope
     vec.push_back(v);
     ^
0_0_18227462_9320.cpp:40:21: error: 'vec' was not declared in this scope
   for(int i = 0;i < vec.size();i++)
                     ^