View Compilation Error

0_0_19997070_28447.cpp: In function 'void DFS()':
0_0_19997070_28447.cpp:39:5: error: 'priority_queue' was not declared in this scope
     priority_queue<node> Q;
     ^
0_0_19997070_28447.cpp:39:5: note: suggested alternative:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/queue:64:0,
                 from 0_0_19997070_28447.cpp:3:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_queue.h:370:11: note:   'std::priority_queue'
     class priority_queue
           ^
0_0_19997070_28447.cpp:39:24: error: expected primary-expression before '>' token
     priority_queue<node> Q;
                        ^
0_0_19997070_28447.cpp:39:26: error: 'Q' was not declared in this scope
     priority_queue<node> Q;
                          ^