PushDownAutomata

// MPAuto.cpp: определяет точку входа для консольного приложения.
//

#include "stdafx.h"
#include <vector>
#include <string>
#include <iostream>
#include <deque>

using namespace std;

class pushDownAuto
{
private:
    vector<char> memory;
    int activeMatrix;
public:
    pushDownAuto()
    {
        memory.empty();
        activeMatrix = 1;
    }
    void pushA()
    {
        memory.push_back('A');
    }
    void pop()
    {
        memory.pop_back();
    }
    void pushB()
    {
        memory.push_back('B');
    }
    void pushC()
    {
        memory.push_back('C');
    }
    int parse(deque<char>& txt)
    {
        while (txt.size() != 0)
        {

            if (activeMatrix == 1)
            {
                if (memory.empty())
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        return 0;
                    case '1':
                    {
                        pushA(), txt.pop_front();
                        break;
                    }
                    case '\0':
                        return 0;
                    }
                }
                else if (memory.back() == 'A')
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        return 0;
                    case '1':
                    {
                        pop(), pushB(), txt.pop_front();
                        break;
                    }
                    case '\0':
                        return 0;
                    }
                }
                else if (memory.back() == 'B')
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        activeMatrix = 2; break;
                    case '1':
                        pushA(), txt.pop_front(); break;
                    case '\0':
                        return 0;
                    }
                }
            }
            else if (activeMatrix == 2)
            {
                if (memory.back() == 'B')
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        pushC(), txt.pop_front(); break;
                    case '1':
                        return 0;
                    case '\0':
                        return 0;
                    }
                }
                else if (memory.back() == 'C')
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        pushC(), txt.pop_front(); break;
                    case '1':
                        activeMatrix = 3; break;
                    case '\0':
                        return 0;
                    }
                }
            }
            else if (activeMatrix == 3)
            {
                if (memory.back() == 'C')
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        return 0;
                    case '1':
                        pop(), txt.pop_front(); break;
                    case '\0':
                        return 0;
                    }
                }
                else if (memory.back() == 'B')
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        activeMatrix = 4; break;
                    case '1':
                        return 0;
                    case '\0':
                        return 0;
                    }
                }
            }
            else if (activeMatrix == 4)
            {
                if (memory.empty())
                {
                    if (txt[0] == '\0')
                        return 1;
                    else
                        return 0;
                }
                else
                {
                    switch (txt[0])
                    {
                    default:
                        break;
                    case '0':
                        pop(), txt.pop_front(); break;
                    case '1':
                        return 0;
                    case '\0':
                        return 0;
                    }
                }
            }
        }
    }
    void getInfo()
    {
        cout << memory.size();
    }
};

int main()
{
    deque<char> input;
    string txt;
    cin >> txt;
    int i = 0;
    while (txt[i] != '\0')
    {
        input.push_back(txt[i]);
        i++;
    }
    input.push_back(txt[i]);

    pushDownAuto *obj = new pushDownAuto();
    if (obj->parse(input))
        cout << "correct\n";
    else cout << "incorrect\n";
    return 0;
}