stack , queue , deque , priority_queue

stack<int> s;
    s.size();
    s.empty();
    s.push(x);
    s.top();
    s.pop();


    queue<int> q;
    q.size();
    q.empty();
    q.push(x);
    q.front();
    q.pop();

    deque<int> q;
    q.size();
    q.empty();
    int x;
    q.push_back(x);
    q.pop_back();
    q.back();

    q.push_front(x);
    q.pop_front();
    q.front();

    priority_queue<int> q;
    q.size();
    q.empty();
    int x;
    q.push(x);
    q.top(); // max element in pq
    q.pop(); // delete max

    priority_queue<int , vector<int> , greater<int> > q;
    q.size();
    q.empty();
    int x;
    q.push(x);
    q.top(); // min element in pq
    q.pop(); // delete min