[template] myStack

#include <iostream>
using namespace std;

template <class T>
class myStack {
private:
    T data;
    myStack *next;

public:
    myStack(T x, myStack *n): data(x), next(n) {}
    myStack(): next(NULL) {}

    void push(T x) {
        next = new myStack(x, next);
    }

    bool pop() {
        if (next != NULL) {
            myStack *D = next;
            next = next -> next;
            delete D;
            return true;
        }
        else return false;
    }

    T top() {
        if (next != NULL)
            return next -> data;
    }

    int count() {
        int i = 0;
        for (myStack *cur = next; cur != NULL; cur = cur -> next)
            i++;
        return i;
    }

    void display() {
        if (next != NULL)
            for (myStack *cur = next; cur != NULL; cur = cur -> next)
                cout << cur -> data << " ";
        else
            cout << "< empty >";

        cout << endl;
    }

    bool empty() {
        return bool(next);
    }

    void sort() {
        if (next != NULL)
            for (myStack *prev = next; prev -> next != NULL; prev = prev -> next)
                for (myStack *cur = prev -> next; cur != NULL; cur = cur -> next)
                    if(prev -> data > cur -> data)
                        swap(prev -> data, cur -> data);
    }
};


int main() {
    myStack <double> D;
    D.push(2.1);
    D.push(1.9);
    D.push(3.1);
    D.display();
    D.sort();
    D.display();
    D.pop();
    D.display();
    D.pop();
    cout << D.top() << endl;
    D.pop();
    D.display();

    return 0;
}