tic_tac_toe

#include <iostream>
#include <string>
using namespace std;
int x, y, n = 0;
char field[3][3];//{ { ' ', ' ', ' ' }, { ' ', ' ', ' ' }, { ' ', ' ', ' ' } }; Двумерный массив для хранения крестиков и ноликов
bool flag = true;

void displayField() {
    for (int j = 0; j < 3; j++)
    {
        for (int i = 0; i < 3; i++)
        {
            cout << field[j][i];
        }
        cout << endl;
    }
}
void changePlayer() {
    if (n == 0)
        n++;
    else
        n--;
}

int main(int argc, char *argv[]) {

    char player[2];
    player[0] = 'X';
    player[1] = '0';

    while (flag) {

        //n = stoi(argv[1]); //Кто будет первым?
        cout << "current player: " << player[n] << endl;
        cin >> y >> x;
        cout << "---" << endl;
        if (field[y][x] == player[0] || field[y][x] == player[1])
            cout << "Error" << endl; //Занято
        else {
            field[y][x] = player[n];
            displayField();
            //Горизонтальная и вертикальные проверки
            for (int i = 0; i < 3; i++)
            {
                if (field[i][0] == player[n] && field[i][1] == player[n] && field[i][2] == player[n]) {
                    cout << player[n] << " win!";
                    flag = false;
                }
                if (field[0][i] == player[n] && field[1][i] == player[n] && field[2][i] == player[n]) {
                    cout << player[n] << " win!";
                    flag = false;
                }
            }
            //Крестовые проверки
            if (field[0][0] == player[n] && field[1][1] == player[n] && field[2][2] == player[n]) {
                cout << player[n] << " win!";
                flag = false;
            }
            if (field[0][2] == player[n] && field[1][1] == player[n] && field[2][0] == player[n]) {
                cout << player[n] << " win!";
                flag = false;
            }
            changePlayer();
        }
        cout << endl;
    }
    return 0;
}