View Compilation Error

0_0_22001330_28306.cpp: In function 'int main()':
0_0_22001330_28306.cpp:33:8: error: 'class std::priority_queue<node>' has no member named 'push_back'
     q1.push_back(node(i,d));
        ^
0_0_22001330_28306.cpp:34:19: error: 'class std::priority_queue<node>' has no member named 'push_back'
     if(o=='B') q2.push_back(node(i,d));
                   ^
0_0_22001330_28306.cpp:42:12: error: 'class std::priority_queue<node>' has no member named 'pop_back'
     res=q1.pop_back();
            ^
0_0_22001330_28306.cpp:44:12: error: 'class std::priority_queue<node>' has no member named 'pop_back'
     res=q2.pop_back();
            ^
0_0_22001330_28306.cpp:52:6: error: 'a' was not declared in this scope
      a.
      ^
0_0_22001330_28306.cpp:53:5: error: expected unqualified-id before '}' token
     }
     ^