View Compilation Error

0_0_2871171_17014.cpp: In function `bool bfs(std::queue<Slave, std::deque<Slave, std::allocator<Slave> > >&, int)':
0_0_2871171_17014.cpp:71: error: `tmp' undeclared (first use this function)
0_0_2871171_17014.cpp:71: error: (Each undeclared identifier is reported only once for each function it appears in.)