View Compilation Error

0_0_13987120_25552.cpp: In function 'int bfs(int, int)':
0_0_13987120_25552.cpp:35:10: error: 'q' was not declared in this scope
   while(!q.empty())
          ^
0_0_13987120_25552.cpp:38:3: error: 'q' was not declared in this scope
   q.push(current);
   ^