#include <iostream>
using namespace std;

const int N = 100;
class CPPStack
{
private:
    char s[N]; //栈的内容保存在s中
    int tp;		//栈顶指示器，栈空为－1
public:
    void init();
    bool isEmpty();
    bool isFull();
    void push(char c);
    char pop();
    char top();
};

void CPPStack::init()
{
    tp = -1;
}

bool CPPStack::isEmpty()
{
    return (tp==-1);
}

bool CPPStack::isFull()
{
    return (tp==(N-1));
}

void CPPStack::push(char c)
{
    tp++;
    s[tp] = c;
}

char CPPStack::pop()
{
    int oldtp = tp;
    tp--;
    return s[oldtp];
}

char CPPStack::top()
{
    return s[tp];
}

int main()
{
    char str[] = {"0123456789"};
    CPPStack s;

    cout << str << endl;
    s.init();

    int i = 0;
    while(str[i] && !s.isFull())
        s.push(str[i++]);
    while(!s.isEmpty())
        cout << s.pop();
    cout << endl;
}